If you have the child for almost two years with no contact with the mother, and you have proof of her not supporting the child...
...how can you stop back pay child support? I filled sole custody, did everything, but they said my diligent search didn't have enough information. How can I get more details to support we made a search for mother?
An affidavit has to be filled out stating exactly what has been done to try to locate her, but that is not what you need. You need to retain an attorney. These things are not something you can just find the right form for and make everything all right. Publishing in the newspaper will not get child support ordered for you. You have to get personal service over her.