I'm really sorry you're having so much trouble at school. One of the things that seems to remain the same generation after generation is that teens continue to be cruel to each other. It would be easy to advise you to "ignore it," but it seems you've tried to do that and it didn't work.

There are a few things you could try--some internal work and some external. First, do you believe any of what the others are saying, even a little, even if you don't want to? Not to imply that these things are true at all, but everyone has insecurities and bullies can usually spot them a mile away and know how to exploit them. Creepy self-doubts can surface, especially in a situation where people are constantly picking at you. If this is the case, maybe it would help to do some soul searching to separate their perceptions from what you know about yourself.

Another thing is, are you the shy and quiet type? If you don't talk to your classmates a lot, the lack of information about you may make it more likely that people would fill in the blanks with what others say about you. Perhaps it's time to spread your wings and expose the "real you," at least the "you" you are today! Provide a counterbalance.

Now for the external work. If you feel truly harassed by these girls to the point that it's interfering with your concentration at school or the enjoyment of your life in general, by all means, talk to your school counselor about the situation. He or she can at least intervene to send the message that this behavior is not okay. Oh, and feel free to take this step first, if you feel you need to.