I hope you're not tossing this girl away because she has bad kidneys...I mean, shit Draz, life isn't guaranteed for anyone. You could die tomorrow. (I say this because of your lack of sensitivity with your "just my luck" comment)
I hope you can look past the fact she has bad kidneys and have a great relationship together (if you really do like her that much). You should consider yourself lucky that you've found a great person that you enjoy and enjoys you.
And from a mathmatically-handicapped person, congrats on the math class