My close friend has leukemia. She won't eat ...

My close friend has leukemia. She won't eat properly & lives with someone she hates and complains non stop. She wont help herself but will just complain constantly. Well I tell her I will not listen to it she gets mad at me. Any suggestions? I told her I will help her as much as I can with her illness but not her constant complaining. I cannot do it anymore it is wearing me down I too have a chronic illness but I look after myself.