Dear Andy
I think your resentment is really coming from a wish that your girlfriend would just get well. Your anger presents as an issue with money and her ingratitude, but you are really asking : "Why can't she just GET OVER all this and come back to me????!!!!!"
I am right there with you. I have to constantly remind myself that my mate is not capable of being there for me. He acts like you describe your girlfriend acting.
After 9 months in my program, all I can say, is get into a program and work on yourself. I am sorry you are dealing with all this. We are here for you.