Now what?

I am deeply worried about my fiance. I have wondered for months where much of his money has been going and it turns out he's been spending it on percocet. I don't know if there is anything else he's not telling me, although I hope he wouldn't be stupid enough to hide stuff from me now that he's agreed to get help. I worry for his life but I also worry about our life together if we get married. Will all of our money evaporate? Will he continually lie to me to cover for his problems? There are so many things that are stuck in my head right now and I don't know what to do.