Didier,
I pray you won't be offended by anything I am going to say.
Reading your post only one word kept coming to mind, and that word was "selfish". Your mom isn't the first person in her situation to do this and certainly won't be the last. She's been through alot and in some people it's the natural reaction. What will change it is the reaction she gets from others. She isn't going to change it on her own, that's pretty obvious. You are enabling her, you and all the doctors. She is healthy enough that if left to her own doing for a week or so she will survive and be fine. Make her do for herself, stop treating her as if she is still sick. Many of us that are two years out and went through surgeries tougher then anything she experienced are self sufficient and she should be also. Only you can end the cycle she is living. She won't do it because she likes it this way, likes being taken care of. Appeal to her motherly feelings, tell her how this is affecting YOUR life. Your mom is not going to lay in that bed and waste away if she is left to take care of herself for a change. Give it a try. Most it can do is make her angry and that's some energy so it's worth it!
I wish you much luck with this.
Minnie