WG, you hang in there. You are stronger than you know. Yes, 50 is very young to die. But you have nothing to feel guilty about. You gave a lot of yourself, despite how she treated you. You have to remember that she did this to herself. The anger will come at some point about that. Dr. Kubler-Ross said that grief has 5 stages: Denial, anger, bargaining, depression, and acceptance. The first four don't always occur in that order, or you might go back and forth between them. I think she should have included guilt, as well. But you must experience them to get to acceptance. Once the funeral is behind you, you can allow yourself to grieve.
My thoughts and prayers are with you.
Hugs,
Connie