I didn't save my marriage, but I see the struggles that people have. The reason my marriage wasn't saved went back before the big bomb. I came home before things were fixed. Very much like the endeavor you are about to undertake with your H.
I am going to sum up your situation. 1) H leaves you holding the bag. 2) H used up everything he had. 3) Now he needs someone to take care of him and pay his bills.
Nothing has been fixed. You want to make him pay. make him fix him self before he comes home. That means getting a job and paying his own bills before he comes home. That means the "happy list" should be the minimum for him to return. And if he does that, then you will really have a chance for a stable relationship with this nut...sorry, man.