Any new Texas laws regarding forgiveness of interest/arreage for orders dated pre-1990

Any new legislation regarding interest / arrearage forgiveness for withholding orders prior to 1990? Have a withholding order that had regular child support and arrears to be garnished. In mid to late 90's, Texas attrny general got new system to calculate interest that essentially double what I originally owned and had paid down. Now past 10 years, while my check gets garnished every week for childsupport or interest whatever it is now, my principal balance maybe shrinks $2-$5 dollar per year. I had an original back child support of ~$25k (100/mo) was allotted to back/arrears until the year 2004; Then all of it ~400/month is now going to arrears, but the balance never goes down.......What are my options. The child is 30 years old I have been paying religiously for the past 20 years and not reduction in balance. Last time attryn. general sent stmt (about 3 yrs. ago) the balance was $30k.