Why did my ratings and league go down?


I think you are mistaken. It does not look like you went back to the wood league. It looks like you were promoted to the bronze league.
https://www.chess.com/leagues/bronze/2MKqFuFfc
/ I do know that you aren't allowed to play on someone else's account.

OH! Thanks about that! I think I almost got myself banned. I looked at it closely and it did seem like I wasn't back to wood league but just advanced lol. But wouldn't I still be getting banned if my brother plays on that account on another device?

OH! Thanks about that! I think I almost got myself banned. I looked at it closely and it did seem like I wasn't back to wood league but just advanced lol. But wouldn't I still be getting banned if my brother plays on that account on another device?
I don't know how the fair play team monitors things. I would just avoid playing on his account any more.