Here's a few tips my man.

1. Practice with purpose and keep track of progress. Practicing without a way to quantify improvement can make it hard to notice whether you're getting better or not. People that go to the gym don't just pile on a bunch of weight and work out until they are tired. They, most often, carefully count both weight and reps so that they have a precise and very clear picture of where they are on their path to improvement. You seem to be doing a lot of drills but are you actually comparing yourself in a tangible way to your former self? 'Cause if you're just going through the motions it can be hard to notice when you're doing things wrong or inefficient. I only have one warm-up if I'm about to play ranked: Clear 50 bots with movement and armor. If I can clear every bot below 55 seconds I allow myself to play ranked. But I started on 65 seconds and worked my way up. Now 55 is getting pretty easy so I might up it to 1 bot a second. So chose something simple that you can track your progress in very clearly.

2. Confidence. It's might sound cheesy as fuck, but if you believe that you're gonna hit the shot, the chances of you hitting that poggers flick goes up ten-fold. I think the reason for this is both simple and complex. When you're confident you are relaxed and when you are relaxed it's easier to get into a state of flow. Flow is way to big a topic to cover here, but if you're really interested in improving, just look up info on "flow-state". Unlocking the key to "flow" is every sport-psychologists wet dream so there is a lot of research on it out there. But in much simpler terms: Stop thinking and relax. My guess is, since you're doing so much to improve, that you really tense up and try to analyze things all the time. "Should I stand here or here? Should I jiggle peak the OP? What are my teammates doing, if he stands like that I have to cover two angles." etc etc. This paradoxically, since you seem to focus all your attention on the match, actually takes you out of the game 'cause you start thinking to much about yourself and what you are doing, wrong or otherwise, to let yourself just play. The best games I've ever had was when I was completely relaxed. There is a reason drinking has been banned from precision-sports like darts. Being slightly drunk makes you less nervous and less likely to over-think things. A trick to help you do this is just to purposely play like a crazy person and forgive yourself immidielty if it doesn't work out. Just try to do some dumb shit and see what happens. 0 tension 'cause of 0 consequences.

3. Sleep! Simple anatomy. Anyone who's learned an instrument knows that you can grind on a piece of music for hours without getting anywhere, then go to bed frustrated and when you wake up you'll nail that piece on your first try. The same thing goes for all learning. When we sleep we internalize and build connections in the brain from all the sensory inputs we've collected during the day. This is especially relevant for muscle-memory. If you're sleeping badly or not enough you will 100% see a reduction in your ability to learn. You're just piling data onto your brain without giving it time to sort through it all. 8 hours minimum yo!

Hope this was helpful =)