I was wondering as I read about your H's change of attitude, if your H was not enjoying feeling needed or like the good guy when he could show you care and concern and be there for you. Now you are not seriously ill and you may be getting a good job. Your life is good and his is still in the toilet.
I am not saying he shouldn't be feeling this, he is totally responsible for his choices and his life. But it was just a thought.
Everything happens for a reason, maybe Dad needs to find that it isn't better out there, he needs to realize how good he had it here. Maybe he will find God and that is the most important thing when he finds Him he will know he is supposed to come home.