I'm so sorry that your daughter doesn't accept what is going on with you and thus can't be supportive. It doesn't sound to me like there is any way you will be able to convince her right now (perhaps the more you try, the more she will resist). I wonder if you can just accept (as frustrating and sad as it may be) that (for whatever reason) this just is the way it is right now, and acknowledge to her that you and she don't agree about this. ("I know you don't believe.... but this is what I am going through" - and/or "this is what the doctor's have told me...." "so I guess we just aren't going to agree about this"). Then try to focus on other things you can agree on, like your grandchildren or things you like to do together. I hope you can find peace with her seeming irrationality and enjoy what you can in the relationship. Maybe in time she will see things differently.