Cycling between sadness and anger is so normal. Understand that your world has been turned upside down and you are becoming desperate for a foothold onto sanity. None of this makes sense. You knew this person better than anyone and you couldn't imagine this ever happening between the two of you.
The challenge is going back to a place where the madness doesn't have a hold on you. Moving there can stabilize you and prepare you to be that "calm in the storm" she may eventually seek out.
I considered who I would want to come back to if I was caught in this wild ride (from my wife's perspective) and it would be someone who was kind and loving, not desperate, patient, and safe. I also knew I wouldn't want to come back to someone who was telling me that I was the person for them and tried to convince me to do the right thing. I realized that I would prefer someone who was stable while I was unstable.
This is still new for you. I hate to see you here but you are. In the meantime, try as hard as you can to not dwell on the negatives and think that it is over and that she doesn't love you or loves someone else. Chances are she still loves you. As for the OM, it is not about love (and that is not just my opinion).
Me:56, W:51 D:26,S:24,S:22 Married:18 Bomb 9/27/06 Separated 11/27/06 Divorced 10/6/08 Leaving it up to God