I need to walk away from mortgage and house for my own sanity and safety. What are the ramifications?

The only answer is to re-evaluated the situation about the house debt and the husband. If you feel you should walk away from a just debt then it's fair to assume you would expect the same if anyone owed you the debt. As for the husband only when he's ready will he get help according to my experience in trying to help addicts. I've lost hundreds of thousands helping addicts only to find it to be a waste of money. Only the addict seems to have the answer. Good luck and god bless you. Go to some support groups for a better answer, it will give you more incite into the problem.