Hi WhatsRight :)
So there are things in the family you need to start taking steps to fix.
The marriage we know, takes 2 people. If he isn't ready or willing you then have to concentrate on the part you can control...you.
Can you start taking baby steps towards your healing, individual of him?
I am sorry for your son, we have dealt with addiction in our home too and it is probably one of the most painful experiences to witness a child so lost and self-destructive. Is he safe? (I assume so, in rehab). Can you contact the rehab to inquire about family therapy to help you all through this? It is definitely a family disease even though he is the one showing the worst signs, family therapy is usually the norm with addiciton.
You cannot carry it all on your own, so choose what needs the attention in the moment and do what you can.
No matter where you lend your focus right now remember to take care of you.