what I was getting at was that I don't have anything more to say
If you don't have anything more to say, then don't say anything.
Re counseling: SHE may go into MC with the idea that she's going to "fix" you, but that's not the way MC works. If the C is worth anything, one person doesn't get to push their agenda to the exclusion of anything else. And what makes you think any reputable C is going to support her position? Hel-LO!
Just hold your ground and ignore the accusations she is making at you. If you must say something, say, "Yes, I do have some insecurities and it's possible I'm depressed. I'd be happy to address these issues and others with you and a counselor as soon as you have broken off all contact with the OM. THAT will be my signal that you're interested in working on the marriage."
It sounds to me like the OM is trying to blow her off, but she refuses to acknowledge the message. Here's another icky anecdote from my past: this guy that I had the A with when I was married-- he and I took a trip together, a driving trip. When we got to our destination, he parked me with some mutual friends, and he drove off another 100 miles or so to see his former girlfriend (she had dumped him). While he visited her for a WEEK, and I cooled my heels with a girlfriend, and my H wandered around back home (what a godawful mess... really painful to remember), my A partner and his former gf decided to make a go of it again. So he came back to me and BROKE UP WITH ME. Then we had the 1,000 mile or so drive back home. I called my H and told him that "A" had dumped me, and he said, "Just fly home right now." But *I* said (and this is the point I'm making) didn't want to make "A" take that long drive by himself! Can you see how totally sick that was? He dumped me and I still wanted to make life easy for him? Yikes!
After "A" former girlfriend moved back to our city and they moved in together, I still wouldn't go away! (I'm making a comparison between myself and your W. I believe her OM is trying to cool it, but doesn't have the b@lls to tell her to GO AWAY and STAY AWAY!) After they moved in together, I drove all around the neighborhood where I knew they were moving until I found their house. I went in (when she wasn't there) and talked to him, still clinging. Finally he wrote me a letter, which made it very clear that they were back together and I was out of the picture. They married and have been together almost 30 years now.
She's probably hanging on, but eventually he will shake her loose. If the A were escalating, she wouldn't be so panicky.
Stay cool. Come here to vent. No "R" talks with her.