I’m so sorry for the loss of your Mum and the trauma you have been through. It sounds as if you were a pillar of strength for your Mother, and, although I’m no expert, I tend to agree with your brother that your Mum was at the end of life and nothing else you could have done would have prolonged her life.
Please know you have nothing to feel guilty about, you did an excellent job of supporting and loving your Mum which will have helped her hugely, despite how it may otherwise seem. She is at peace now. Take care of yourself and please keep talking if you need to x
