Oh, trying! It sounds so similar! I'm just beginning to understand the underlying relationship issues, but I think they closely relate to yours.
I have been described as selfish and not allowing WS to have a voice. I was told I was overbearing. I own aspects if that, but it was the interaction of our behavior in the relationship that got us where we were in the relationship. But it was WS alone that made the decision to stray.
I, too have become more affectionate and am allowing her the space to have a voice. But it is her discoveries about herself that are both improving helping us improve the relationship and rebuilding trust and confidence in her ability to maintain healthy emotional boundaries going forward. SHE made the decision to not use her voice. SHE made the decision to avoid conflict and agree to whatever I said...even when I encouraged her to do things for herself. I won't own all of it. And it was HER that chose to risk everything by hoping to not get caught by making an ugly independent decision instead of risking a conflict in the relationship by being genuine about her thoughts and feelings.
She came to me and revealed her realization of these things. We are still working through it, but without that I couldn't move forward. For us, I think the separation and the 180 have her the time alone to figure out if I was an obligation or a want. With us together she couldn't tease it apart. She spent our whole relationship making it about me without me totally realizing it. I was so oblivious that I didn't even know how bad it was until I discovered the first EA, and didn't know the full story until DDay 2. Because of our similar relationship issues and because it looks like you've been together a long time, I wouldn't be surprised if there are more instances of betrayal in some form, if only getting emotional needs met by others that blurs the lines of an EA, if not directly at least an EA. He's protecting something, if not just his fragile ego or the realization that he needs to be accountable.
For my WS, it seems that revealing the worst or all of what she did and being remorseful is in some way connected to the idea that it will make her pain from how she believes I treated her a non-issue. She didn't want it to be all about me because then her pain becomes negligible and I might stop trying or trample all over her again (her words).
Read up on codependency and the persuer/distancer communication pattern. It helped me tremendously. I think the threads that led me to the information were in the WS forum.
As far as your situation, I'm not sure what to say. I'm not in your shoes and obviously your child's well being is important. I will say that being vulnerable to him right now will most likely bring more pain. I'm still in a balancing act of what to share and how to share it to protect myself from more blame or rejection.
Does he know this isn't working? I mean, does he really know? Does he want R? Is he doing the other work, like NC and transparency?
It sounds like he's trying to stay with the least amount of work possible, and you deserve more than that. Much more.