I'm afraid I have no words of advice either. All I can say is this.....back to the trust issue.
Is he earning your trust? Doesn't sound like he has a clue how much trust his R with this OW is eroding. He is in the same pattern he always has been. That is his comfort zone. You have your own comfort zone and he doesn't seem to fit into that.
Do what you need to do for your own wellbeing. That's all I can say.
I'm here for you!!!
BTW, are you in the alt?
T19 M15 S19 XH47 M43 bomb12/4/07 PA5/07 S12/26/07 D final 11/17/08 Back together with no defined R 05/2010 confused....to say the least!!!