If you haven't confronted him yet about the OW, then that is the first thing you should do. Actually I'm surprised you haven't done so already seeing as how he's telling everyone she's his "soulmate".
Oh and don't pay too much attention to that "soulmate" comment. I think we've all heard it. Blah.
So confront him by saying something like you know he has OW. You love him, but will not stand to be disrespected as you are his W. He'll say something like that's why he's asking for a D, etc. But hold up your hand and repeat that as of this moment you are still his W and deserves the same respect that he would expect from you since he's your husband.
Don't issue an ultimatum, just make your stand confidently and strongly but with no anger. That's the toughest thing you will ever have to do, but you can do it.
Retrouvaille works only if both partners are honest with one another. With OW in the picture, it's going to be tough and his focus will be on her and not you.
If you're going to show PMA, you have to make it real and not "forced". Which means to a certain degree you have to detach from him emotionally. Kind of like acting in a role. You pull back your emotions enough so that you aren't constantly asking if what you're doing is right or why is he doing this or that.
You detach to protect yourself. Think of yourself as the WAS. I believe this is something you need to do asap since Retrouvaille is coming up.
He may very well still be in there, but you need to dispel the fog he's in. Not with a hand fan, but with a hurricane.
M-43 W-40 2D - 9 and 5
Emotion, yet peace. Ignorance, yet knowledge. Passion, yet serenity. Chaos, yet harmony. Death, yet a new life.