TLDR; I signed a post nup, it was one sided, later we signed a no contest divorce agreement, can crazy ex retoractively go back and enforce post nup despite finalized divorce agreement?

So I've been going through a divorce the last year. No kids. The divorce was no contest and everything was finalized by a judge in may. I am still on the mortgage and am trying to work through clearing that up and the ex is hiding things, lying, gas lighting, and is unable to refinance. Divorce decree says she has to sell by a date(which has passed), I was willing to be a good person and give her a chance but she has doubled down, threatened and blackmailed me, and says she will take me to courts with the post nup that pretty much says i get nothing. Am i protected from this post nup since a no contest divorce agreement was signed with no mention of a postnuptial? Situation sucks because I have little money and she has a family friend that is a powerful family law attorney and will help her as much as needed pro bono. I should feel welcomed to the club of divorcees with terrible ex's. Interesting experiences that i wouldn't wish on my worst enemy lol