Here's an outsider's perspective: It's astonishing how you've made all of this your problem.
It's not! He's not your husband of 20 years, he's not your son or your father or your only sibling. He's some dude you've had some dates with. You don't owe him a thing.
It's funny how a dysfunctional childhood will sneak up on you. You'll feel yourself in control of life, happy, successful, and then suddenly you find yourself wrapped up in some loser's drama just because you want to feel needed. (At least, that's how it's been with me!)
Focus on the good things in your life and have some fun. He'll either join the living again or he won't. Nothing you can do about that.