MSH, the sitch with your kids is getting complicated. I wish I could give you some solid advice to help. You know this but I would try to remove them from the sitch as much as possible. The problem is your W does not seem to be helping with this and is putting all of this on your shoulders and that is very wrong.
I wonder if it would be helpful to take the kids away for a week or so and get them out of this sitch for awhile. I feel what your W is doing is borderline child abandonment. I she even trying to have some R with D13?