I think it is wonderful of you to want more for your girlfriend. It is quite possible that she has her own issues, those of enabling. She probably thinks that if she stands by you that you will get better, when instead, she is just getting sucked into your illness.

Maybe you should tell your girlfriend that you love her so much that you think the best thing to do is take a break so you can focus on yourself. Let her know that you are doing it for her, but be clear that you are not asking her to wait for you to get better. Let her know that if she finds someone else, that you understand.