That's good HH sorry to you hear about your condition.
I'm going to say something a little bit rough now. but I say it from a place of knowing about it from my own experience so please don't think me awfully judgemental. I am, as well, judging myself.
I think you a respect problem for your DH. I think this is why sex is a struggle (often women find it difficult to be sexually attracted to men they don't respect) and also possibly why you had an affair. The reason I'm raising this is because if you don't address THAT, I think you're liable to do it again.
Here's why I think that. You refer to him with terms like 'angel', overly pure and almost implying a child-like naivete and perfection that's not manly and certainly not realistic. It's the sort of term we use for someone who's 'behaved well' but is on the same level as us in some way (either up or down). You think you are not 'the wife he deserves', this is the language of someone with one foot out the door. You're already envisaging the other wife, the next one who can take over and salve your guilt for leaving. It's not YOU. It's not YOU being better and surer and kinder. The wife he deserves is YOU if you want to be.
He has told you, literally told you, what he wants. He wants full disclosure from you, about what you are doing and what you are feeling and this is not an unreasonable ask, considering. You immediately discount that. Why? Because you feel very guilty, apparently. But look closer. I have no doubt you feel profoundly guilty, but that's not why. If the truth is that you would turn away OM, or future lovers, then whatever emotional rollercoaster you are going through would be difficult but helpful for your husband to hear. And difficult for you to admit. So you are running away from your own discomfort. Apparently for 'generous' reasons, you are finding a way to AGAIN hide things from your husband, and AGAIN ignore his wishes. But you are phrasing it as being philanthropic. This is very dangerous and narcissistic. When women exhibit narcissistic traits they do it differently from men. Because women are raised to be always thinking of others and subtly masochistic, this is where the lies we tell ourselves get spun, what we hide behind. But this pretense of masochism is very very narcissistic. It focuses again on you, not him really. When you talk about going to him to share and for support you worry That it makes YOU selfish, that it makes YOU wrong. Who cares? He has been shut out of you life for ages and just wants to share and support. Do what he asks. If you really feel guilty, do what he bloody asks. Shut up about you.
To despise oneself, you need to have a great deal of respect for the part that despises.