I think the most important thing you could do for her and yourself at this point is to stop drinking WL. And think about what she'd want you to do. Holding resentments against your other relatives is pointless and will only hurt you.
I'm sorry that your mother is in this condition, a good friend of mine just passed away last week in hospice and was only in his mid 40's. He was literally a skeleton of his former self but right up until the time that he lost consciousness for the last time he asked people pray for him and to help take care of those around him after he was gone. I learned a lot from him without him saying any words.