I'm sorry you've hit this part of your R, DG. It feels like one more nail, I know; I had a similar situation this past Friday when W was at my house for a cup of coffee. We talked, laughed, had a warm interaction just like old times...and then she asked when we would start mediation.
We can't stop the runaway train. We can't change the past. I know what you mean about replaying in our heads all the wrongs we inflicted on our S's. But we can't own all of the problems; it always takes two to create or tear down a marriage.
You have used a very painful situation to become a better person. Your H has not. You have looked inside yourself and taken out the trash. Your H has not. When you reach a point where you might consider another R with someone you will be well-equipped to have a healthy, loving and stable R. Your H will not.
This has been the most painful situation we have experienced, but I would rather be us than our WAS's.
H 56 W 48 D27,S21 SS25 SS22 Severely autistic M(#2 for both) 9 1/2 yrs. "I've never loved you" 3/7/2011 Separated 8/7/2011 BITS