Can a person make me sign something in order to recieve money from a court order, can they withhold that money if I don't sign?

I served my ex-husband served papers to enforce judgement of asset money that was in our divorce. He hadn't paid me yet after a year. I served him in July and he has a court date in Oct. On Aug 31 when dropping our daughter off for his weekend visitation he handed me papers that I had to sign in order to receive the money. This paper was typed by him and stated that I would cancel the court date and I would not pursue any other legal stuff against him. I did not know if I could cancel so I aid no. I can't remember exactly what the part about legal stuff was word for word. I do know he wanted me to not be able to do something I may end up needing to legally. He took the paper and told me that if I want the money I need to sign the paper. Should I just wait until Oct. and let him pay me in front of the judge and is he able to make me sign something in order to receive money that I was awarded in the divorce settlement that he hasn't paid after a year.