I'm so sorry, I can really sympathise with you. My mother had cancer last year and I went through a whole range of emotions. The thought of having to take care of her in a physical sense made me feel sick, but not caring for her made me feel extreme guilt. She has recovered for now, at least. Its very complicated when there is a complex history. Just do what feels right for you -only you can decide. I really feel for you...Take care. x