I'm so sorry for your loss, I too know what it feels like to lose a mother, i lost mine when she was 58, seems so young. Nothing any of us can say will make u feel better right away but you know that she is no longer suffering, I truly believe it is harder for us to lose someone because when someone passes on they watch over you and their loved ones every second of the day howeverall we have is the memory of them, we are not lucky enough to watch over them every day, we have to wait a lifetime. Your mum would want you to be happy she is no longer suffering the pain and she would be proud that you stood by her through this.
keep your chin up