That is because you are on the defense, and you shouldn't have to be. I speak from experience, because I have done the same thing. What could we have done differntly, better, been more patient, yada yada. And it is good to focus on that and try to correct it, because we can all always better ourselves.
But remember, it takes two, and you were not the only one in this marriage. He may not be taking responsibility for his part, but that doesn't mean you have to.
Im still standin better than I ever did looking like a true survivor feeling like a little kid Im still standin after all this time and Im picking up the pieces of my life without you on my mind..