I'm sorry Bev, that's a shitty situation to be in. I have no useful advice because it's out of my ken.

I have a stepfather turning 80 who lives in a house that is falling down (he has no water in most of the house anymore, and there are legit trees growing out of the eavestroughs) but won't move or for the most part accept any assistance. However, apart from a few other quirks --he feeds the cat with a standing pile of dry food in the middle of the kitchen floor--he's quite compos mentis. My sister's family lives nearby and pick him up for dinner once a week but he steadfastly refuses most help of any other kind.

Still a thousand percent better than your situation. All the best.