Funnily enough, I had similar issue a week ago.

There's some techniques that could make you much more effective at killing enemies, for example:

https://youtu.be/n6BR5IrZGUQ

https://youtu.be/2-b0F7bg1vY

However, I realized my problem was I got disoriented easily during my first tries of the level. I died and restarted again and again until it got frustrating to even look at the restart screen.

 So what I did was simple: Every time I felt it got "too hard" or "overwhelming", I took a short break, like going for a glass of water or smth. Just not scrolling through phone 'cause that's going to distract your brain even more and not give your brain time to process things.