And that queen proceeded to systematically dismantle you.
Chess is a two player game, you cannot be too caught up in your own plans to counter your opponent, or miss the opportunity to punish them when they blunder.
“When you see a good move look for a better one.” - Emmanuel Lasker
On your second most recent game, you simply lost on time.
This is why I recommend primarily playing longer time control games at a lower level.
More instructive moments, and more time to calculate, and in doing so you will cultivate your ability to calculate.
When cultivated up to a certain point, you will be able to calculate more deeply, seeing more complex and subtle tactical opportunities.
Tactics puzzles aid in cultivating your ability to spot tactics, and truly get them ingrained in your head.
This is crucial, because as you climb the rating ladder, your opponents will also be rather skilled at tactics, and so you must be able to spot them in order to not fall pray to them.
Case in point, in my second most recent game, I let my guard down and fell victim to a basic tactic, wherein my opponent checked my king and took my light squared bishop for free.
Also, remember the idea that it is often not the first blunder that loses you a game of chess, but the second or third.
In the aforementioned game, I got stressed due to falling for such an obvious tactic and hung a rook a few moves later.
As IM Levy Rozman of Gothamchess always advises, look for checks, captures, and attacks (for both you and your opponent).
I strongly recommend doing a large quantity of puzzles every day, a minimum of 10 (I myself do 20-50) they are unlimited on sights like lichess and chesstempo.
Also, there are many hours of free instructional chess content on youtube, from channels such as Daniel Naroditsky, Hanging Pawns, Gothamchess, Saint Louis Chess Club, Eric Rosen, John Bartholomew, and more.
I hope this post helped, if only slightly.
Following the points I describe above, I went from the 800s-1600s since November.
Everybody is different, so that's why there isn't only one general way to learn. First of all, you have to discover your biggest weaknesses in the game and start working on them. The most effective way for that is analysing your own games. Of course, if you are a beginner, you can't do it efficiently because you don't know too much about the game yet. There is a built-in engine on chess.com which can show you if a move is good or bad but the only problem that it can't explain you the plans, ideas behind the moves, so you won't know why is it so good or bad.
This is not one of those posts where I complain that I want to quit(I don't) but I am finding myself stuck in the 900s. I have been playing for a while, but here, whenever I get a win streak, it is immediately followed by a streak of losses that drag me right back to where I was. My goal is to double my rating in 6 months, but I can't seem to improve. 1: Is this streak of losses following every win streak normal? And 2: Could you look at my recent games, and see what I need to improve? The computer is useless in that context, and it has been a while since I have gotten feedback from a human. Thank you.