"Rustie, I agree, we are getting things said. It really hurts to hear them, but we have both been holding in for 13 years."
I remember after my H's affair the huge discussions we'd get in. Things "came out" that had never ever been said. At the time I thought I hated all of that. Looking back on it now, I realize it was a big part of what helped to bring us back together.
Some of it (a lot of it?) may hurt. But I believe that you need to really consider some of the things that he is saying to you. Think about if you could change some of the things that he mentions are problems.
One thing that really stood out to me was the comment your H made about these communications "helping" him. That, I believe, was a complete give away. If he is "done" .. what does he need help with?