My best friend is my crush?

Well it seems like you are in a very tough situation. If I were you I would just try and be really good friends with the guy you like, this way you won't be involved with his drama and you won't have to worry about him liking/not liking you. Also, you won't have to get in the middle of your other friends relationship with him. Maybe in the future after all of it settles you may have a future dating him. But until then try and date other guys. Open some new doors and have fun with it, and remember you are only 13 you still have you whole life ahead of you.