Solid advice from above .... And it will be new thread time for you aswell but I have been wanting to chime in a bit here as your latest "Kids spending the night with H" does hit a nerve/home with me.
I am a father, did not ask for this but I know for a fact that if my W tried to stop the kid(s) from spending time this would be a conflict waiting to happen ..... and with MLC if you read up the reconnecting phases work backwards. He will want to connect with the kids and you should not be the gate keeper in this.
A very wise woman on this board said "you can be right or you can be happy". Think about where this fear of allowing the kids to see their father is coming from and really ask yourself if this is good for the kids, you, and your H.