It sucks but it's part of adolescence. Basically what the above poster said. Ignore them, get through it, don't escalate it, bulk up a bit if you want to, but stick to your friends and things that you're good at which will improve your self-esteem. There's nothing really the school can do unless someone actually hits you, unless they try and get involved and make things worse by making you look really weak. In a couple of years you'll think that was a sh*tty time but look where I am now.