My credit is ruined due to past due child support

Yes, past due child support will appear on your credit report. You will never be able to purchase a home or a new vehicle. What can you do? Nothing. It is a valid debt that you are ignoring and you need to pay it. Also, at 6% (it used to be 12%!!) interest on past due child support, you are looking at the debt growing and growing. Soon you will be paying interest on interest.