Dear Amy, my thoughts and prayers are with you during this sad time.
Of course you are not ready to let your mum go. As witches said, no one is ready to say goodbye to a much loved mum.
And of course you are angry........angry at the bus who hit your mum, angry at Dr's who have let you down, angry at family members who have upset you at anytime over the past couple of years and perhaps even angry at your mum for having this accident in the first place.
That is all perfectly normal.
So go and punch the heck out of a pillow, if someone has a punching bag, get stuck into that. Scream into a pillow and curse away........cry and cry.
You have been incredibly strong for so long. Yes, you may have had your 'moments', but for the most part you have been the one to hold it together, to be the strongest advocate for your mum ever since the accident happened.
2 years is a hellova long time to be this stoic person for your mum, and for your dad, and at the same time, be a wife and mother and try to have some sort of normal life.
Your mum has fought the good fight, but now her body is telling her that enough is enough and I am sure she welcomes the peace that passing over would give her, because I don't doubt [after rereading this thread last night], that she was fully aware of what had happened and how it was affecting her family, even if she couldn't communicate that to you.
I do hope that the end comes quickly for her, and that once things have settled down somewhat, that maybe you and your husband can have at least a few days away, somewhere nice, where you can regroup and relax.
Sorry for the scroller Amy. I am sending you huge, huge hugs.