@BlackAphrodite: I am sorry that you have to go through this. My advice would be, to first see if there is a teacher, family friend, relative that you can confide in. If there is no one, withdraw, stay calm and keep a low profile. Build yourself up from within yourself and concerntrate on being strong. Keep a record with dates and events of exactly what kind of abuse transpires. Make sure to keep it private. Concerntrate on school, get good marks so that in a year or two you can get out of that environment. If you feel you can no longer bear it, go to the cops, if that happens, your diary of events, on paper will be a good back up.
Stay strong, don't let this define your whole life, you are young and have your whole future ahead of you. Hold on to that within yourself, eventually you will get out of that situation. You are welcome to reach out at any point.