Can’t find good moves in mid game

@miau41 Your problem is probably related to not understanding the activity on the board, meaning which are the threats, or what is about to be threatened, or what you should not do because of the rival's activity.
Here are some reading possibilities that I often mention:
https://www.chess.com/article/view/how-to-play-positional-chess
https://www.chess.com/article/view/test-your-positional-chess
https://www.chess.com/article/view/do-you-really-understand-positional-chess
https://www.chess.com/article/view/get-ready-to-test-your-positional-chess-again
https://www.chess.com/article/view/can-you-pass-this-positional-chess-test
https://www.chess.com/article/view/how-to-calculate-long-term-advantages-in-chess
https://www.chess.com/article/view/learning-basic-pawn-structures
https://www.chess.com/article/view/learning-pawn-structure-for-chess-players-under-2000
https://www.chess.com/article/view/your-pawn-structure-is-your-friend
https://www.chess.com/article/view/more-pawn-structures
Simple Attacking Plans by Fred Wilson (2012)
https://web.archive.org/web/20140708090402/http://www.chesscafe.com/text/review874.pdf
http://dev.jeremysilman.com/shop/pc/Simple-Attacking-Plans-77p3731.htm
Logical Chess: Move by Move by Irving Chernev (1957)
https://web.archive.org/web/20140708104437/http://www.chesscafe.com/text/logichess.pdf
The Most Instructive Games of Chess Ever Played by Irving Chernev (1965)
https://chessbookreviews.wordpress.com/tag/most-instructive-games-of-chess-ever-played/
Winning Chess by Irving Chernev and Fred Reinfeld (1948)
https://web.archive.org/web/20140708093415/http://www.chesscafe.com/text/review919.pdf
Back to Basics: Tactics by Dan Heisman (2007)
https://web.archive.org/web/20140708233537/http://www.chesscafe.com/text/review585.pdf
https://www.chess.com/article/view/book-review-back-to-basics-tactics
https://static1.squarespace.com/static/5856bd64ff7c50433c3803db/t/5895fc0ca5790af7895297e4/1486224396755/btbtactics2excerpt.pdf
Seirawan stuff:
http://seagaard.dk/review/eng/bo_beginner/ev_winning_chess.asp?KATID=BO&ID=BO-Beginner
https://web.archive.org/web/20140708090229/http://www.chesscafe.com/text/review492.pdf
http://www.nystar.com/tamarkin/review1.htm
https://web.archive.org/web/20140708092617/http://www.chesscafe.com/text/review560.pdf
50 Essential Chess Lessons by Steve Giddins
https://web.archive.org/web/20140708100833/http://www.chesscafe.com/text/review534.pdf
http://www.gambitbooks.com/pdfs/50_Essential_Chess_Lessons.pdf
Amateur's Mind by Jeremy Silman
https://web.archive.org/web/20140708094419/http://www.chesscafe.com/text/ammind.pdf
https://www.silmanjamespress.com/shop/chess/amateurs-mind-the-2nd-edition/
Simple Chess by Stean
https://web.archive.org/web/20140708104258/http://www.chesscafe.com/text/review400.pdf
http://store.doverpublications.com/0486424200.html
Silman’s Complete Endgame Course
https://web.archive.org/web/20140708103149/https://www.chesscafe.com/text/review594.pdf
https://www.silmanjamespress.com/shop/chess/silmans-complete-endgame-course/
https://theweekinchess.com/john-watson-reviews/theres-an-end-to-it-all
In the middlegame, tactics are usually prevalent so always looking for tactics and practicing tactics can help. If you can't find any tactics, just try to find the least active piece and then try to move it to a better square.
Also look at each of your opponent's moves and try to find the idea behind them

In the middlegame, tactics are usually prevalent so always looking for tactics and practicing tactics can help. If you can't find any tactics, just try to find the least active piece and then try to move it to a better square.
Also look at each of your opponent's moves and try to find the idea behind them
That is horrible advice.

In the middlegame, tactics are usually prevalent so always looking for tactics and practicing tactics can help. If you can't find any tactics, just try to find the least active piece and then try to move it to a better square.
Also look at each of your opponent's moves and try to find the idea behind them
Incorrect. Tactics are not usually prevalent in the middlegame. As the saying goes: "Tactics flow from a superior position." You want to have tactics in the middlegame? Do the following:
Have a space advantage.
Place your pieces on active squares.
Create/Find weaknesses in your opponents position.
You do give good advice regarding making your pieces active. Though that should be something you do in all phases of the game.
As far as finding good moves in the middlegame?
Double check your moves.
Play slowly.
Calculate out as far as you can.
Look at forcing moves first.

In the middlegame, tactics are usually prevalent so always looking for tactics and practicing tactics can help. If you can't find any tactics, just try to find the least active piece and then try to move it to a better square.
Also look at each of your opponent's moves and try to find the idea behind them
Incorrect. Tactics are not usually prevalent in the middlegame. As the saying goes: "Tactics flow from a superior position." You want to have tactics in the middlegame? Do the following:
Have a space advantage.
Place your pieces on active squares.
Create/Find weaknesses in your opponents position.
You do give good advice regarding making your pieces active. Though that should be something you do in all phases of the game.
As far as finding good moves in the middlegame?
Double check your moves.
Play slowly.
Calculate out as far as you can.
Wrong, what matters is not how deep you calculate but how well you evaluate the resulting positions.

In the middlegame, tactics are usually prevalent so always looking for tactics and practicing tactics can help. If you can't find any tactics, just try to find the least active piece and then try to move it to a better square.
Also look at each of your opponent's moves and try to find the idea behind them
Incorrect. Tactics are not usually prevalent in the middlegame. As the saying goes: "Tactics flow from a superior position." You want to have tactics in the middlegame? Do the following:
Have a space advantage.
Place your pieces on active squares.
Create/Find weaknesses in your opponents position.
You do give good advice regarding making your pieces active. Though that should be something you do in all phases of the game.
As far as finding good moves in the middlegame?
Double check your moves.
Play slowly.
Calculate out as far as you can.
Wrong, what matters is not how deep you calculate but how well you evaluate the resulting positions.
That is why i stated it as: "...as far out as you can."

In the middlegame, tactics are usually prevalent so always looking for tactics and practicing tactics can help. If you can't find any tactics, just try to find the least active piece and then try to move it to a better square.
Also look at each of your opponent's moves and try to find the idea behind them
Incorrect. Tactics are not usually prevalent in the middlegame. As the saying goes: "Tactics flow from a superior position." You want to have tactics in the middlegame? Do the following:
Have a space advantage.
Place your pieces on active squares.
Create/Find weaknesses in your opponents position.
You do give good advice regarding making your pieces active. Though that should be something you do in all phases of the game.
As far as finding good moves in the middlegame?
Double check your moves.
Play slowly.
Calculate out as far as you can.
Wrong, what matters is not how deep you calculate but how well you evaluate the resulting positions.
That is why i stated it as: "...as far out as you can."
I can calculate 20 moves ahead, but there is no point in calculating that far because I will certainly miss something.

In the middlegame, tactics are usually prevalent so always looking for tactics and practicing tactics can help. If you can't find any tactics, just try to find the least active piece and then try to move it to a better square.
Also look at each of your opponent's moves and try to find the idea behind them
Incorrect. Tactics are not usually prevalent in the middlegame. As the saying goes: "Tactics flow from a superior position." You want to have tactics in the middlegame? Do the following:
Have a space advantage.
Place your pieces on active squares.
Create/Find weaknesses in your opponents position.
You do give good advice regarding making your pieces active. Though that should be something you do in all phases of the game.
As far as finding good moves in the middlegame?
Double check your moves.
Play slowly.
Calculate out as far as you can.
Wrong, what matters is not how deep you calculate but how well you evaluate the resulting positions.
That is why i stated it as: "...as far out as you can."
I can calculate 20 moves ahead, but there is no point in calculating that far because I will certainly miss something.
Lets keep this on track for the OP's sake. This isn't about you, or me. As they say: "Lets agree to disagree."

In the middlegame, tactics are usually prevalent so always looking for tactics and practicing tactics can help. If you can't find any tactics, just try to find the least active piece and then try to move it to a better square.
Also look at each of your opponent's moves and try to find the idea behind them
Incorrect. Tactics are not usually prevalent in the middlegame. As the saying goes: "Tactics flow from a superior position." You want to have tactics in the middlegame? Do the following:
Have a space advantage.
Place your pieces on active squares.
Create/Find weaknesses in your opponents position.
You do give good advice regarding making your pieces active. Though that should be something you do in all phases of the game.
As far as finding good moves in the middlegame?
Double check your moves.
Play slowly.
Calculate out as far as you can.
Wrong, what matters is not how deep you calculate but how well you evaluate the resulting positions.
That is why i stated it as: "...as far out as you can."
I can calculate 20 moves ahead, but there is no point in calculating that far because I will certainly miss something.
Lets keep this on track for the OP's sake. This isn't about you, or me. As they say: "Lets agree to disagree."
The point is that positional understanding is the most important aspect of the middlegame.

In the middlegame, tactics are usually prevalent so always looking for tactics and practicing tactics can help. If you can't find any tactics, just try to find the least active piece and then try to move it to a better square.
Also look at each of your opponent's moves and try to find the idea behind them
Incorrect. Tactics are not usually prevalent in the middlegame. As the saying goes: "Tactics flow from a superior position." You want to have tactics in the middlegame? Do the following:
Have a space advantage.
Place your pieces on active squares.
Create/Find weaknesses in your opponents position.
You do give good advice regarding making your pieces active. Though that should be something you do in all phases of the game.
As far as finding good moves in the middlegame?
Double check your moves.
Play slowly.
Calculate out as far as you can.
Wrong, what matters is not how deep you calculate but how well you evaluate the resulting positions.
That is why i stated it as: "...as far out as you can."
I can calculate 20 moves ahead, but there is no point in calculating that far because I will certainly miss something.
Lets keep this on track for the OP's sake. This isn't about you, or me. As they say: "Lets agree to disagree."
The point is that positional understanding is the most important aspect of the middlegame.
That is obvious. But the OP is asking how to not make blunders, and find good moves in the middlegame. That is why i answered as i did.
Double check your moves.
Place your pieces on active squares.
Look for forcing moves.
Calculate out as far as you can.
After looking at some of the OP's games, he is making blunders in all phases of the game. The OP would really help himself by following the advice of double checking his moves, and playing slow time controls.
"... Sure, fast games are fine for practicing openings (not the most important part of the game for most players) and possibly developing decent board vision and tactical 'shots', but the kind of thinking it takes to plan, evaluate, play long endgames, and find deep combinations is just not possible in quick chess. … for serious improvement ... consistently play many slow games to practice good thinking habits. ..." - NM Dan Heisman (2002)
https://web.archive.org/web/20140627052239/http://www.chesscafe.com/text/heisman16.pdf
It might be of interest to look at the table of contents of A COMPLETE CHESS COURSE by Antonio Gude: "... 1 The Basic Rules of Chess 7 ... 2 Your First Chess Games 23 … 3 Openings and Basic Principles 33 ... 4 Putting Your Pieces to Work 52 ... 5 Strategy and Tactics 76 ... 6 Endgame Play and Further Openings 106 … 7 Combinations and Tactical Themes 128 ... 8 Attacking Play 163 ... 9 Your First Opening Repertoire 194 …"
http://www.gambitbooks.com/pdfs/A_Complete_Chess_Course.pdf

As a kind of a beginner myself, I can give one tip that changed how I approach the game for me: learn positional chess. Knowing pawn structures, how the value of your pieces is not as fixed as you might believe, and more importantly, how to evaluate a position, was a game changer, at least for me. By that, I mean that you can at any given point, see and point the flaws of your and your opponent pawn structure/pieces that are inactive or bad placed. It'll naturally give you ideas during the whole game, because you'll be always looking to exploit those flaws, trying to improve your general position and generate passed pawns for your endgame, etc. For literature on that, I can recommend Bruce Pandolfini's "Weapons of Chess", as he put all these concepts in a quite simple manner.
For blunders, I say keep practicing tactics, at least that is what helped me. I still suck at tactics, though, and many games I won by outplanning my opponent more than anything, so like I said, some positional understanding is a very powerful weapon at this ELO.
Also, I just took a look at some of your games, and you might want to take a look at the basic principles of opening and some openings, so you have a repertoire. It's not necessary for you to learn a ton of openings, but you might want to have a white opening, and a response against 1.e4, 1.d4, and 1.c4.
Hi. I have similar problems of not making good moves during mid-game. That's why I always play defense. Even when I play White, I still make conservative moves. No risks taken.

Ya, play defensively when not in need is playing passively. It works up to a certain level of opponents.
Building an attack, on the other hand, presumes that at some point the attacker will put his pieces in unprotected squares, thus increasing the chances for hanging up one when not paying attention. Nonetheless, when winning it's because of you and not because the rival was kind enough to mess things up.
Ya, play defensively when not in need is playing passively. It works up to a certain level of opponents.
Building an attack, on the other hand, presumes that at some point the attacker will put his pieces in unprotected squares, thus increasing the chances for hanging up one when not paying attention. Nonetheless, when winning it's because of you and not because the rival was kind enough to mess things up.
My motto for chess: My motto for chess is the same as my motto for soccer: Play conservatively, find weak spots, attack.

In soccer, playing conservatively is denying the space to the opposing team, waiting for the opportunity when the opposing team messes things up.
In chess, playing conservatively usually means playing passively, with everything well-defended in the own field. That said, the chessboard tends to be wider than the soccer field. Check the Capablanca-Scott game in the article https://www.chess.com/blog/Nicator65/the-space-level-amateur
In soccer, playing conservatively is denying the space to the opposing team, waiting for the opportunity when the opposing team messes things up.
In chess, playing conservatively usually means playing passively, with everything well-defended in the own field. That said, the chessboard tends to be wider than the soccer field. Check the Capablanca-Scott game in the article https://www.chess.com/blog/Nicator65/the-space-level-amateur
They both play defense well. For soccer, check out Real Madrid in 2010-2015. They're excellent at counterattacks.