It is possible to have a MSA where you just agree.... but you both have to trust the other. In your case, there's just no way that's going to happen.
If he wants to file for D, that's up to him. For you, it's time to Lawyer up, and make sure that you do whatever you have to to protect yourself and the kids. It's not about raking him over the coals, it's about protecting yourself.
