I can't say "I know how you feel" or anything like that. It's never happened to me, but I can say I've had problems with people who were supposedly my "friends" in the past, and I think you're doing the right thing. In my case it was one of my very best friends, and it was really hard to cut her out of my life at first. But in the long run, I think it's worth it. So good for you for not letting them bring you down! Good luck.
By the way, love your shirt. :)