I agree with Io. You need to talk to your friends, but first, I suggest talking to the girl that is causing the trouble. Tell her that you don't appreciate her doing this to you.
Along with Io, I tend to want to please all of my friends. That's not a bad thing, but when it comes down to my emotions, sometimes I just back out. If your friends aren't listening to you when you tell them how you feel, back out. Seperate yourself from them and give you and them time to think. I know it's hard being without your friends, but if they are going to treat you that way, they aren't very good friends at all.
Please keep us updated on your situation! If you need anything at all, plaese feel free to PM me.
Good luck
--Mel-- <3