I understand you have mixed feelings about the counseling, but everything you wrote here tells me that overall you DO want to be there. You want to communicate to your W that you are willing to work on the marriage if she stops her affair, and you want to find out where she stands on that. That sounds to me like you want to be there, at least one time, if not more.
I would have replied, "Yes, I want to be there."
Me: 50, MLC/WW 45 Young kids Nov 2015: BD1 Apr 2016: BD2 Jan 2017: W filed Feb 2017: D final