How do I accept that my 71 y/o father seems to have given up... and blames me & my mother for it?

I've been lurking here awhile, finding great solace in the things I read all of you inspirational people say. But I've cried twice today so maybe it'll help to stop lurking and start talking? I feel like I should apologize before I start...

I live with my parents. My father is 71. This doesn't seem old to me at all. But my father has an extensive medical history (heart attack, bladder cancer, left side weakness, mobility issues). He was forced to retire, for medical reasons, in 2018. He fell down the stairs in early March of this year and the ER sent him home after diagnosing a C7 vertebral fracture that they said would heal on it's own. Then he had serious mobility issues later in March and was admitted first to the hospital for four days of observation and then into the skilled nursing rehab associated with the hospital. He was there for just over three weeks.

The diagnosis ended up being a sacral fracture and fused vertebrae in his neck, from a previous broken neck. There were no signs of stroke or Parkinson's or anything... the neurologist said physical therapy was what would help more than anything at all.

He did so well in rehab. They called him the star pupil and said he'd be in PT all day if they let him.

My mother and I were so hopeful.

Then he came home.

They sent a PT and and OT, for about two weeks, and gave him pages of exercises to do. The OT told him about how if he takes a day off, he loses three days of strength... and it takes 30 days to get it back. She told him that the choice to exercise and to do the work was his, and his alone. She told us about how her father let her sister and brother-in-law do more and more for him until he couldn't do anything for himself and he started falling and his organs started failing.

Maybe she pegged him as someone who would choose not to do the work.

And she was right. I knew that before he went in, after he blew off PT after hand surgery and basically lost use of his hand, even if I didn't want to admit it to myself.

But I hoped it would be different because he worked so hard in rehab.

And then he mostly stopped doing the exercises and stopped working for anything, just like he did between when he retired and was hospitalized. He changed the exercises to be easier, but did them less often. He picked about five that were easiest and calls that done. We sat with him and did the exercises with him, and he claimed we wanted him to exercise 24/7 and be in 'perpetual motion'.

But he constantly lists the things my mother and I don't do for him, even though he doesn't do anything for himself and he will choose sitting and staring at the television every time rather than working to be better. He won't talk to us. He won't be a part of things. But he complains that we leave him out of things, that he's not a part of things. And I've heard my mother beg him to talk to her, about her or about him or about me or about my sister... and he won't.

I ask him why he isn't working harder, why he hasn't found something worth fighting for (even my sister's kids, his grandkids). He tells me I ask loaded questions, don't give him credit for trying, make unfair demands...

And I just want my father to not give up, to not color his choices by claiming he had no choice because my mother and I wouldn't let him exercise, to not turn away when I beg him to work to be a part of my life for as long as possible.

Am I wrong? Did I do something wrong? Because he makes me feel like I did, and I end up thinking awful things about him sometimes - and sometimes I say them, and sometimes he says awful things to me.

He apologizes for that a lot, and so do I, and then he promises to be better, to talk to me more. And then he doesn't.

I couldn't even tell a doctor what's going on, because he doesn't talk. That's what my mother and I told the ER and rehab staffs. We don't know, he doesn't say.

Thanks for listening to me. And thanks for all the words you've already said.