He can't stop a divorce. In most every state...all debts are 50/50 even if only one ran up the bills. Unless it can be proved that bills were run up over the past month or so to inflate things (new car two weeks ago, all new furniture 3 weeks ago) All assets would be counted as 50/50 as well. Selling the house to pay the debts vs keeping the house and the bills that go with it so to keep the family home for the children...support is based on income of each as to who pays what if the house is not sold. So from his standpoint, selling the house may be the better option.
There are consequences to our actions. He will need deal with them and you can't protect him from them but to soften the blow of his consequences ...
Maybe talk things over with one of the councelors at the rehab before talking with him. Deal with each issue one at a time.
She wants a divorce...issue #1
All other issues will be worked out later...one at a time.