Can i fill my own papers to lower my child support in texas an how..her frist lawer is now the judge.?

I have an ingery and trying for SSI I have rotator cufes compley detached right an left this happen in may 2009 itsgets worse I have been mentel hospitl twice for depression an havent seen my 12 year old sence july or my other dauther that is 22 years old no money or insurance any more CAN ANY ONE HELP./