You already know your own answers. Contacting the OW puts them on center stage. They don't belong there. It takes your eyes off the real issues. Forget her.
You need to keep things in their place. The OW has no place in your life. You can't keep her away from your H but you can work of your focus. Focus on your life, the things you control.
This whole process can play out any number of ways. You need to set your goals so that you have the best chance to get the outcome you want. Your H does not know everything about the OW yet. They have not been together long enough to know each other completely. It will take time. There is a great chance that time will take the shine off their A.
In that time you will want to keep from becoming the evil one. Be his friend as much as you can. Treat him fairly, as long as it does not violate reasonable bounds. In time, he will begin to see you as his best friend again, and the OW will show her colors. This often happens.
But more than all that, you will look back in time and see that you took the high road and became above all that is wrong in the crisis. That needs to be one of your goals. And you do need to come to see that this is all about time ... and what you do with it. What you do for yourself in the meantime, and how you make the best life with your kids.
Your H may be getting coached by OW. He may be having some control issues. Or he may be thinking that giving up too much at this time could set a precedence for future decisions. You can't expect answers to why he is flipping around. As long as he is flopping within a fair middleground you should be ok, right?
Patience will become your strength, so feed on it. And start reading about Detaching.
