The reality of the situation is fear controls people, first you need to rid yourself of the fear, the threat of physical violence is enough to write a letter to the head of the school informing them you fear for your personal safety, make sure you only hand in a printed copy of the letter and have it signed, once they acknowledge your situation the fear will lift, then if you still fear for your personal safety, you will need to report the situation to the police, basically use the laws, school policy on bullying ask for a copy at reception, provided you take every action available to you within the law and use it to your advantage you will win. There are laws about negligence, school's have a responsibility to protect people from violence, maybe carry around a spy camera, use your knowledge, knowledge is more powerful then fear when used correctly , you can’t fear something if you know how to stop it from happening .