I too agree with what everyone has said here already. Is it possible to talk with her and get her input? If you are clear with her about the confusion and ups and downs as you negotiate your way through this healing process and the unknown outcome, perhaps she may be willing to be supportive and continue the relationship? If she is included in the process, it may take some of the tension out and she'll see your symptoms for what they are (and not a personal attack on her) You learn how to manage your symptoms with some outside feedback (hers and others).

I've found it shocking how many people that I thought were friends are no longer even in my life since my accident. It really showed me who is real in my life and who was not all along anyway, I just couldn't see it before the accident exposed them. As painful as all that was, my life is much less stressful without them.

My vote is that you include her in the discussion about your unknown path and rethink the breakup, take Mark's advice and become more familiar with each of your symptoms and see if she is up for continuing on. If not, then she wasn't going to be there for the long haul anyway and better for you to know now. Hang in there!