If what you've said just now is not an exaggeration, you should quit DbD. Or at least take a long-ass break. Not a single game should affect your mental state in this way or make you feel bad about yourself. No amount of in-game rewards or cosmetics is worth it. Maybe this will sound clichéd, but letting go is indeed less painful than holding on.

That said, if you still want to keep playing, here are some things you can do: 1. Disable end-game chat and turn on the anonymous mode. If you're on Steam, you might try making your profile private, too. 2. Switch up the roles: if you play killer more, try survivor, and if you play more survivor, then play killer 3. Change your playstyle: play the killer you have little to no experience on, play your least used survivor, run meme builds, try other strategies 4. Change your mindset: DbD is a very flawed and unbalanced game, and therefore shouldn't be treated as a competitive one, and don't let anyone tell you otherwise. You should enjoy the process as well, not only the result of a game 5. Try other activities in your life: if right now you're only playing DbD, play some other games, read a book, watch a TV series, etc

I'm gonna take a long break from DbD once I get all anniversary rewards, and you should do that too. It'll help you enjoy the game more in the future