My ex-girlfriend and I agreed in child support court to stop support and do shared parenting. The court agreed to this and stopped the support that day. When we left we decided to handle the agreement ourselves instead of filing a motion for shared parenting through the courts. Two months later she got mad at me and decided not to let me see him anymore and is now taking me back to court for support. Is our oral agreement in child support court for shared parenting legally binding or can they order me to pay support again?

No, your oral agreement is not binding, only court orders signed by the judge are. She may default back to the original written and signed paper work as the valid,