First of all - this claudia chick seems to be a high maintenance friend.
Look at yourself girl...you're unhappy! This girl...no matter how good your friendship once was... is causing unhappiness in your life. You can always make new friends. I think that you need some time apart from her so you can find your feet again.
Friendships are not ment to be complicated. You like somebody, and they like you. So you decide to hang together. That is what a friendship is. Is it worth all that other $h!t that is happening?
Just rethink it all over mate, I mean...Obviously i dun't know you or the claudia girl in person so perhaps i'm taking it all wrong...but i would seriously rethink if it is worth hanging around her or not.
stay strong girl! we're all here for you