I agree hat this is a terrible idea and one that will almost sure lead to "failure" and heartbreak. If he says he isn't drinking and you are certain he then there is already failure.
I know it isn't what you want to hear, nor was it for my parents who watched me nearly kill myself, but you simply can't do it for him.
With more job loss, more devastation,you will get to choose one thing: whether to stay, or not.
Best to you for getting support for yourself.