unadoption laws of PA.

I adopted a child while I was married. My ex-wife is her biological mother. Soon after I adopted her things started to go sour. We seperated. Six months later she divorced me. I still think the only reason I was supposed to adopt her was to make sure her mother would receive a check each month For child support, since the childs biological father was never going to be found. The child and I have no relationship because of her mother, but I am forced to pay child support each month. What if any are the laws reguarding the unadoption of a child in Pennsylvania? Any information would be appreciated.