Hey Joellee~ Well, I am really sorry to hear that. You have done all that you can and your Mom needs to be at peace. It's hard to understand that right now, and it's still a little raw or me, as you know I have been there.
Feeling helpless is hard and saying goodbye is even harder, but Mom knows you love her and she loves you all... that is why she has made the decisions she has. She's only saying Goodbye for now, so it's really more of a "I'll see you again someday". Just try to imagine Mom in the best spa treatment of her life, w/no pain and only joy when she goes to the Lord.
I am keeping you, your Mother and your family in my prayers.
You know I'm here if you need me.