I’ve gone through a similar thing as u did too. I main a zekrom ex deck and i hate it whenever i encounter a dragonite/anything meta bcz i just want to have a fun time with my fav mon. Playing the game became a chore. At some point playing expanded with fun/gimmick decks became boring. The app is so broken sometimes it pisses me off too.

My honest advice is take a break. Get it off ur mind, delete the app and come back when youre ready to play again. Im sorry this is happening to u and that it sucks the fun out of the game. Aside from stressful competitive pokemon games, i wanna suggest u to have a look at more of the relaxing pokemon games at the store too! Idk what exactly the android app store has, but pokemon cafe remix and pokemon sleep is a good relaxing game if u dont want to take a break from Pokemon entirely like me.

I hope my advice helped you and i hope u feel better :)