Have you spoken with the school counselor at all? If not, do so. If yes and he or she was not helpful, I'd recommend scheduling an appointment to see the headmaster/principal. Above all else though, you need to start documenting what's happening to you. Stick with very straightforward, objective stuff. Do not put any emotion, opinion, or perspective into the documentation. If the principal is unhelpful, you should go to the school board or whatever the next level of authority happens to be.