I just want to say one thing: he'll die if you leave him to fend for himself? Well, too bad then. Yes, I know, I'm being incredibly harsh here, but you need to look in the mirror and ask yourself: is he my husband, or my pet? Am I his wife or his mother? Why should he even try to get his act together if everyone around is taking care of him? He's living a comfy little existence now and there's no way he'll give up on that until you cut the apron strings. If he loved you, he would want you to take care of
yourself first, and live the life you wish, with or without him. You've putten his needs over your own for years: I'd say it's time you claim
your share of the pie that is life.
P.S. About his pets: maybe you could take care of them? If you do leave him, you wont have to worry about them and you'll have some company!