Child support legal advice please!!!!!!!?

in the state of texas, can the attorney generals office increase child support payments based on pay without notifying you? my husband makes considerably more than he did 8 years ago when he first started paying child support and now his pay is being reviewed. we havent even started having a family and are trying to save for that, and now we might not be able to because double the money might be taken out. is that fair? his ex is on her 7th child and she gets all kinds of govt istance and we never have, and now we might have to feed her all her kids? this is wrong and an injustice! we are hardworking medical professionals, what legal rights do we have? he has only one child who is now 11 with his ex. and she never even sends any clothes anytime the child comes, so we end up buying a whole wardrobe every summer and christmas, and pay for all the plane ticket when the ex is supposed to pay half. and we had to buy the child a cell phone bec, she couldn afford to have phone service! i am very upset and need some help, fast! the ex is saying she didnt provoke the att. gen office to increase payments and doesnt want anymore money, but i don't buy it. if she is telling the truth, can some kind of agreement be reached so that we dont have to pay much more?