I'm really sorry Ashley. I don't really know what to say, but here goes.
I'd suggest you find some new people to hang out with, and stop any contact with those girls whatsoever. If they send you a message, delete it. If they say something, ignore it. Don't let it get to you. You're so much better than that.
If you want,
pm me the site they bully you on. I'll register and kick their butt for you, if you'd like x3