Oh May - where you are is hard, but I do think you are where you need to be.
I can share some experience with you? H and I don't really talk about his EA anymore (and I do acknowledge in the scale of infidelity, his was small potatoes compared to what your H has put you through - that offence to your marriage and wound in your heart.) I'm satisfied I know all I need to know, and I am satisfied he is behaving absolutely faithfully to me today. But if we both told our stories about that time, they'd be different. H would use words like 'unfair' and 'not having my needs met' and those are true stories for him. And I'd use stories like 'feeding your ego' and 'you had other options' and 'you felt comfortably lying to me' and those are true stories for me. I don't think our stories will ever totally match, and I am not sure that is necessary for healing. He knows how much it hurt and why it hurt, and I think I do understand a bit of what was happening for him at the time and why it was linked to how he was experiencing our marriage at the time. I think we both have blind spots, and the choice was fairly clear - I could either accept his view, and require him to accept mine, we could agree on that, and work on a new marriage where we could care for our relationship in such a way that we'd never slide back to that place again. Or we could keep on arguing, forever, that he'd never understand exactly why and how it was so painful to me, and I'd never understand how he felt he had no other options. So we left it behind, and I do think my heart has left it behind too. I don't know if that is the healthiest or the best way to do it - I talked about it a lot in IC and we never have productively in MC (though I am open to that happening someday if we need to) and I don't feel I am in denial or suppressing anything in order to stay in my marriage.
And all that is heart work. The action that follows heart work could have been us divorcing, and me deciding that I didn't want to be open to trusting him again (that is a work in progress, but I do want to try) and that would have been a good decision if it was the one I needed to take.
I wonder, May, if you need to accept that there are aspects of your experience - as a woman, as a mother, as a friend, in your professional and creative and spiritual life, and in your healing from this terrible wound - that he isn't going to understand because he isn't you. There's always a kind of existential privacy inside marriage, and I can't help but wonder if you are stuck because you are expecting him to understand your pain and anger in a way that just isn't possible. Maybe instead of asking him to get up close to it and really see it, your job is to get up close and see it very closely for yourself? Perhaps that is what your IC was getting at? You can ask him to respect that, and you can also - perhaps - respect that there are aspects of his experience you won't ever know or understand. And that is where trust comes in. Trust yourself first, then you will know if you want to learn to trust him or not very clearly.
I also - and this might be left-field - wonder if you need some kind of ending-ritual. He never moved out. You never ended your marriage, and you have not yet begun your new marriage. I am not suggesting anything as public as a divorce or a vow renewal, and this might not even have to involve your H. But I am remembering how affected you were by him throwing out all those old trinkets and letters - the ritual and action of that. Is there something you can do - some skin-on-action - that is about ending that old marriage? Really burning it down and getting rid of it? Clearing the decks for something new - whatever that might look like, either you alone or together? Maybe in time you'll have some kind of reconnecting ritual (a friend who went through something similar threw her wedding ring off a bridge and a few months later, accepted a new one from her H - maybe you don't need anything as dramatic as that!) Could that be something that your H is attempting with the bedroom renovation? Maybe you can't start something new with him not because he's not sorry enough, or not understanding enough, or not rid of the OW enough (you will never ever KNOW that - and that isn't because he is dishonest, or has been - it is because you can't live inside his head so sooner or later you will have to trust, or accept you don't trust anymore) but because you have not really let the old thing die.
Just some thoughts. Have a digital covid-safe hug from me.