Mom, let it go. I know that's easier said than done, but what's past is past, nothing can be done to change that.
You need to concentrate on the challenges still to come, and the future and what it holds for not only the two of you, but the family as well. Talk to the councilling staff at the hospital. They're there for you too, as well as the family.
Use them freely, and embrace what they tell you. They CAN help, and WILL help...let them
Wayne