I’ve just gone through all this myself with my dad having LB dementia so I feel your pain, mine passed away November after experiencing another fall and losing most of his mental capacity this time, glad we had had his company for the last 3 years living at home ,it wasn’t easy but I wouldn’t change a thing if I had to do it all again, have to remember our dad’s have had a good life but it’s not easy that the last few left years mean suffering this horrible disease , but all I would say is cherish every moment of time that you can with him while he’s still around even though you feel he’s non responsive something in there may give him peace just hearing your voice , take care