I have 2 kids with my long time boyfriend I never wanted him on cs but he was placed on Cs for 1 we never paid it and are now oweing 7,000?

We have been together for 13 yrs and he was placed on CS for our oldest. We maade a few payments and stopped after a few because the money came right back to me figuring what's the point of paying if it comes right back to us? So now we received 2 packets in the mail stating we are being sued by the attorney general? I mean.. I don't want him to get into trouble. He has jobs here and there and I've been an Medical asst for the past 6 going on 7 years and without him Idk how we would be able to have someone pick our kids up from school or help watch our kids while I work long hours at work. I mean I honestly don't have alot of money and live paycheck to paycheck trying to provide for the family. Any suggestions on what we should do?