Umm...get a lock on your door. Continue to stand up for yourself even if it's your mum/mums boyfriend or whoever. Oh, and yes, make plans to move out, and even if it doesn't eventuate for a while, you still have something to look forward to.
this mite not be very helpful but continue to stick up for urself even if they ground you, sneak outta the house via a window lol & do ur best at college that way when u complete what ur doing u can get a brilliant job and really rub it in their faces when u have loads of money to move out, revenge on people like that can be a great medicine ur very brave though for sticking out all this bullying, ur obviously a strong person