Unlike child support, spousal support is often very difficult (if not impossible) to modify after the divorce is final, so getting it right the first time is a must!
Are you locked into a lease on the new place? Are you sure that you want a divorce and there is no possible reconsilation? If so then got to an attorney and file for the divorce. Let the court set temporary orders so that he can’t sale, destroy, abuse, etc… If you do file for divorce talk to your attorney about the TRO. Explain to the attorney that you fear that he will not keep up with the mortgage and you are afraid to stay in the home with him. You may be able to stay in the home until the divorce is final. The court will most likely order you to pay spousal support of some sort because of the income differential.
-------------------- Don't stop until it sounds expensive!