I agree, salvage whatever you can and set it out of his reach and take your name off anything that could bring you bad credit.
He is out of control, in denial and he has left you in a very bad position, financially and emotionally.
Can his dad talk to him about getting help, since he's not listening to you?
Is there a Gambler's Anonymous near you? It has helped many who are gambling away their homes and their families.
I am so sorry you are going through this and hope you can keep yourself from sinking with him.
Hugs