Sounds like very selective memory. I'm sure there were times when she was terribly annoyed at you -- but that's called a normal marriage. Not fair nor real to paint the whole marriage that way. You don't ... shag someone you can't stand.
Whether or not it saves your marriage, I think it *is* good for your W to think through these irrational thoughts and memories w/ someone. Since she's decided to blow up your marriage, she ought to countenance the whole carnage she's about to create with a clear view. Is it decided that you're not going back to MC?
When she gave these warped view of your marriage, what did you say? What did the counselor say?
Me: 50, MLC/WW 45 Young kids Nov 2015: BD1 Apr 2016: BD2 Jan 2017: W filed Feb 2017: D final