It is very common to get very frustrated in situations like this. Ultimately it does have to be up to him to obtain the care he needs, and there is no one who can make him.

You have to monitor your health as well. Just remember, some of the most important things is sorting out "whose stuff is who's" to deal with. Ask yourself, what part of this is really mine to deal with?

Sounds like the main option here is for him to get better and hopefully re-kindle the relationship from his progress. The question is; at what point do you set a boundary that draws a line for your own personal health. Be strong. Good luck to you.