Is it possible I have Fibro?

I am almost 15 and I CANNOT wear a traditional bra if my life was on it. I keep wanting to pull it down, and I've gotten several fittings; I'm a 32-B. It is soooo annoying and painful, I don't know what to do. but if I'm not wearing a bra, I don't experience any pain. I can only wear the kind of bras that come down to your belly button. even then, it's uncomfortable. is it just a stage? it's been like this since I was 12. When I was 10 and wore bras, it didn't bother me. what can I do about this? :(