Why does this girl hate me ??

She's obviously very insecure with herself. You'd have to be pretty miserable to be that immature and constantly pick on someone. High school can be horrible, life gets so much better when you're done it. You really do need to ignore this chick. She wants to get a rise out of you. Don't have your friends talk to her, just tune her right out. You are better than that, it's not worth your time!! She'll move on to someone else soon... Good luck