I am tired simply reading about your last few days.
So something has to give, something has to go...
The obvious place to start IMO...
H and MIL. Let it go, AD. H is a grown up who needs to either go to his mom's or not, and you don't need to check up on him.
MIL... I know you want the kids to have a R with their GM, and they want that as well. They aren't little. Next time, let them make the contact with her. Hand them the phone and let them call. If you need to get involved re: scheduling or transportation, then do so. Otherwise, let them do it. Or let your H do it on his own.
Reality of most divorces is that the inlaw family relationship ends or at least fades.
Give yourself a break. Find YOUR priorities. Before you breakdown.
"Acceptance doesn't mean resignation. It means understanding that something is what it is and there's got to be a way through it."--Michael J. Fox
