i keep playing games im really bad at, which i like watching from time to time but only make me feel like a dumbass cos i lose costantly (mainly chess).
after that, i tell myself im good for nothing, and i go back into a depressive/anxious spiral that can last half a day if i dont manage to calm myself down, but even after that i try to try again the day after, which one might think is the good and honest thing to do, right? like trying again to try to improve? but then i lose another couple of games/do badly at the videogamez and it restarts all over again and i cry on myself again. i know it might sound like im exaggerating but i think it's some sort of self harm.
and im starting to doubt if im good at anything, cos i really am not. like the only thing i've been more than ok at for the past two years or so is my high school math, which, tbh, is going great, im helping out basically all my friends pass, but even slightly outside of that i am complete trash at stuff, like not even worth trying.
You're helping all your friends pass math? Do you realize how awesome that is? That means you're not just good at math, you're a good friend. That's one of the best things you can be in this life. I'm still friends with all my best friends from high school and they make my life so much better every day. Sounds like they're really lucky to have you in their lives. Don't stress about not thinking you're good at stuff, just live your life, find new interests, explore them, and have fun. Not everything has to be about being "good" at something, often times simply experiencing things is perfectly fine.