You are still very young in your 20s so there is no need to give up on her yet. Many people have these kinds of health difficulties at this age but can still go on to lead happy lives. It's actually a good sign that you are prepared to support her and wait for her rather than just walking away, some guys your age would just leave at the first sign of trouble, so it's nice that you want to be there for her. I would give it time, let her take the time and space she needs to deal with her problems, be there for her even just as a friend, then see where things are once she is in a better position in her life. You don't need to make an all or nothing decision yet.