Back Child support

[millerlife43]

Married in 1979, had two children (1980 & 81), divorced in 1985. The father and his parents took the kids. (No drugs, no abuse involved, didn't have any money or a place to live) His parents raised the kids on and off until they were 17 & 18.
In 1998, when the two were 17 & 18, (the older one living on her own), the father decided to take me to court for "Back" child support,($30,000). So far, since 1999 I have paid out $10,000.
I have struggled financially throughout the past years. And still struggle. Since then, I have two other boys, now teenagers from another relationship whom live with me. I am newly married and we all depend on my husband for financial support of our household. I drive my boys to school as there is no transportation. , I am currently unemployed, however have been employed with various job positions in the past and am looking for work.
My boys have been on Medicaid for many years and currently reapplying as my younger son has migraine headaches, sees a neurologist every 3 months, and there is no private medical with their father or my husband and we cannot afford $200.00 plus a month for medication.
Any job I get child support is taken, 50%. My two older children from 1980(child support enforced) are now 24 & 26, and have lives of their own.
Because I am 5 months in arrears(can't make full payments of 200.00) on my payments, they want to suspend my driver's license.
My husband is an OTR driver, not employed that long with the trucking company, he barely makes enough for rent, bills, full support of my two boys, etc. Takes two checks to pay for rent ($550.00), electricity not included.
I am looking for work and intend to start paying support once I get a job.
My sons that live with me, their father has terminal cancer and lives in a motel, and cannot financially support my two sons.
What if anything, can I do about this?

Have you been back into court to argue for a reduction?

and..Were you in court when the back support was first ordered?