Daylily, I am just catching up here.
I am so sorry for what you are going through. I feel for you, being in a similar (yet not so dire)situation with my mom, I understand how helpless you feel. Since my mom has been in and out of near death several times now, but is severely incapacitated still, and when coherent, is not particularly fond of being in such a state....we have all just let it go. Let go of the wanting it to be resolved, wanting it to be different, wanting more for her, wanting death for her, wanting her to either get better or go to rest...
It's so very hard, and I hope you will take what I say with love as I give it...but we cannot control these things, even though we think we can by reducing meds, increasing meds, changing venues, etc....
Like most painful situations, it's a matter of sitting still in the pain of it all, and just accepting that it hurts, and that we cannot know, as humans, what to do all the time. Death is one of those places where that reality hits us the hardest at our core.
Sending you and your mom: peace....faith.....love.