You are trying to tell her she can't do what she wants. "You can't go out all those nights, what about the kids?" You're trying to control her and stop her from doing something. You're actually just pushing her further away by doing this but in your desperation you think she will come to her senses. She won't.
Let her be the crappy parent, you be the good parent.
Don't let her guilt trip you. You want to take all of the blame for the failure in your marriage, that way you can fix it. But it's not all your fault and you can't fix her.
You're pursuing and playing games. Be the husband, dad, and person you want to be. Find the strong, happy person inside of you and work on that. And if you stop trying to convince her that she can't do what she wants, then maybe she'll see this person and think that maybe the grass isn't greener on the other side.
As for the D mediator, how did you respond? Have you spoken to a lawyer about any of this? You need to, and you need to tell your W you will be talking to your lawyer whenever she brings up legal issues.
H 34 W 29 BD 3/12/18 Divorce Busted Spring 19
It is not things that bother us, but the stories we tell ourselves about things.