No doubt the tactical training over these last several months have helped. However, I feel like I am still missing "the big picture" of chess as I get tunnel vision swimming compulsively in the concrete pool of tactics and endgames in the vast chess world of strategy and openings. I felt lost during the opening and middlegame of every game, just constantly calculating defensively (still missed simple threats), trying to survive until my opponent blunders and a tactical motif appears or I see an opportunity to trade down favorably.
I think you just described every single one of my games when I was trying to make the transition from crappy E class player to crappy C class player a few years ago. It does pay off though, as you've seen in your results. You need more games to get the experience of when it's worth calculating deeply and when it's not.
Every time I study something that isn't simple tactics, I hit that point where the analyzed lines given for teaching purposes is clearly beyond my skill level, and I need to go back basic/early intermediate tactics, learning to calculate a couple moves ahead, and be aware of the concrete tactics on both sides of the board, or I just keep losing.
I played in my first blitz tournament in over 3 years, scoring 4.5/7, managing to win 1, draw 1, and lose 2 blitz game to different players 500+ points rated higher than me, while winning 3 against players within 100 points of my rating. My blitz rating went up over 150 points (still low, though).
In my standard tournament, I scored 2.5/6, played up in every game, beating 1 player 260+ and another 350+ points rated higher than me (he went Goring Gambit as White maybe because of my lower rating), drawing 1 player 200+ points higher than me, and losing 3 games to players each 300+ points higher than me... 1 of those games, I was up a rook for a pawn then I simply hung my rook (AAAAUUUUUGGGGG G--D--N M-----F--K-R!!!). The other losses were me missing a forced mate-in-2 (seriously?? still doing this?!) and hanging a pawn and then a knight. And for all the hangs, these were literally 1-move hangs, not sophisticated counting errors or brilliant combination hangs.
No doubt the tactical training over these last several months have helped. However, I feel like I am still missing "the big picture" of chess as I get tunnel vision swimming compulsively in the concrete pool of tactics and endgames in the vast chess world of strategy and openings. I felt lost during the opening and middlegame of every game, just constantly calculating defensively (still missed simple threats), trying to survive until my opponent blunders and a tactical motif appears or I see an opportunity to trade down favorably.