My mum is my mum. She can't speak, doubly incontinent, but she eats for England.
Essentially I lost her years ago. All the laughing and the chats, but she's still here bodily. I get a kiss off her once in a while and that makes me happy, but she still holds my hand.
I can understand your anger, but your mum didn't want this and neither did you.
Perhaps you should channel your anger at the Alzheimer's. It's not your mum's fault and somewhere deep deep deep down you know she still loves you, cos I know mine still loves me.
To see her sat up in the nursing home lounge makes me happy as she's looking around, so she's still there underneath it all.
Look for the good signs and days and enjoy them.
Hope you feel better and calmer soon