There have been 2.
Yea, I blocked her so that even if she replies, I won't get it.
I agree with you that if things aren't good inside your marriage it causes problems, both partners have a responsibility if the marriage is in trouble.
I have to agree with dadfor6 on this, to initate contact with the OW doesn;t help heal in the long run. Yours was a betrayal of friendship, which puts it in a completely different category. And I think yiou handled it well.
I had way too many conversations with my ex's OW#3 (I thought she was #2 at the time, but I was wrong).