Is it wrong to discuss your girlfriend's medical stuff with your friends during a break up?

Yes you definitely have a right to be mad. If she is a nurse then she should know better than anyone about the HIPAA laws that govern privacy. She should not have told any one about your health problems that was not cool at all... I would tell her that what she did was not right, and maybe kick her a** in the process...If I were you, I'd take legal action against her asap. Good luck.