Switching classes won't make this go away. Imo, you should probably step away for a little while and come back. It seems like you're acknowledging that playing the game isn't something that's super healthy for you rn. Take a while to go away, come back, and see if you can enjoy the game again. If the past 13 years are any indication, it will be here when you get back lol
If you don't enjoy your time playing TF2, there's no reason to play it. I 'quit' taking it incredibly seriously 3-4 years ago now. It's not like an esport where there are any huge stakes. The ONLY reason to play is to have a good time, and if you don't enjoy it... stop. It's one of the best decisions I ever made. Grades turned around, I got healthier, found the love of my life, worked on friendships with people that put up with me never being available, the list goes on.
And if I get the urge to come play some pugs... guess what, it's still there for me. The game's still around. And I suck at it a lot more than I did when I had 60 hours every week, but guess who cares? no one! Still fun.
Best of luck, robln.