I have a lot of debt that i need to pay or dispute.

I recently applied for a federal job and was put "on hold" because of my bad credit. i was divorced in 2004 but hadn't lived with my wife since 2000. She had our car and furniture repoed, and it was in my name. not to mention the credit cards that were left unpaid. i've disputed these items twice and some of them have been removed. in the divorce decree, the judge ordered that my ex pay the car and furniture debts, but she (ex) i snow incarcerated and the collection agencies are coming after me. they are Hilco rec, Midland credit, capital one bank, palisades collections, and colectrite. my hopeful employer is giving me thirty days to prove that the debts are not mine or being paid by me. i have four children, work full time and go to college. my ex doesn't pay child support and i can't really afford to pay the requested payments. what do i do?