There is an affirmative defense for inability to pay. Only your income, if any, would be considered for repayment.
The warrant is a capias because you probably missed a hearing. You can get an appointed lawyer if you cannot afford a lawyer. If you are able to reach an agreement on a payment plan with the AG, then you may not have to go to jail for very long, if at all.
I practice in this area and would be happy to help.
This is not the sort of problem that might go away if you ignore it, so I encourage you to talk to a family lawyer about your situation. As my colleague who also answered your question said, it is quite likely the warrant out for you is a capias for failure to appear at a child support enforcement hearing. With the assistance of a lawyer, you can come in to the court, be sworn to reappear at the next scheduled hearing, and eliminate the risk of getting picked up on the capias and going to jail. If you do nothing and then get arrested on the outstanding capias, you will be spending at least a day or two in jail while the system processes your case through, but you can avoid that issue entirely by voluntarily presenting yourself to the court. The court's purpose in issuing the capias was to get your attention to the problem, not to punish you for disobeying the court orders for child support. Of course, the underlying problem of you having not paid child support for several years must be addressed to avoid being held in contempt of court at the enforcement hearing, but your attorney could advise you of your options on that as well.