Divorce Support Forums: Livin" like in hell

Hi to everyone
First i want to say sorry for my bad english, i'm german.
I need help and i hope someone can help me. The problem is, my husband ex wife went to the child support because she said she dosent get the money for theire son, but he pays every month (he's in the Army), so the child support office took his money 3 times without saying anything from his pay checks, he went every month to the child support to show them that he's paying.....they belive more her than he. Than he pay $700 for his son, but we've a new family and i'm 7 month pregnant and he earns only $3800 everymonth in the Army, so we have only $2100 every month for 4 person.....ist there something to change the money for the child support? The other thing is, she earn more money than him and his son live in hell, he stink like hell and he's playing between dog shit and get nothing from the money, it's only for her, also she tried to kill herself 3 times in front of his son. What can we do?