loves I don't see this situation as bleakly as perhaps you might think. I actually think it's capable of remedy, but for that to happen, both of you need to revisit the power dynamic in your relationship.
I think people are capable of change, but they normally need the most enormous incentive to do so. I can only tell you what I see from what you write and you know yourself and your H better than any of us here.
It might help you while he is away to draw a timeline of your relationship and look at the power dynamics at different points. You don't say much about his feelings about his behaviour during his first marriage and I wonder what he shared with you about any lessons learned and his attitudes to fidelity and cherishing a partner in the wake of that experience? You also don't say how you have rationalised that story - and the way he treated his first wife - in your own head for all these years?
It sounds as though you have always looked up to him and been in his shadow somewhat, although you might tell us that this has become more pronounced since having children and you have had less independence.
It has always seemed to me that you two have never discussed fidelity in any depth and I wonder where you learned that it was better to be tolerant of friendships that threatened? I wonder whether he has complained in the past about women being irrationally jealous and distrustful and you have therefore tried very hard not to be like that?
I think he loves you and that he loves and values his family. But I do think he sees himself as having the power in this relationship and I do think he has got used to controlling events.
You know I have always said to you that you need to give yourself permission to be yourself and admit when you feel threatened, belittled or small. You've proved to be a powerful advocate for your DCs, now you need to be one for yourself.
I think it's worth having a discussion with him that has ground-rules before you start. What ever you say to eachother, the other will not ridicule or attempt to stop the other talking.
Then you tell him what is in the open domain. You chart how you have been feeling since all this started last year and explain where you are at now, feeling disengaged and giving serious consideration to a future without him. Insist on equity throughout and get him to reverse your positions as I did downthread. From what you've said, you've tried to do this before and his response reveals that he wouldn't have accepted this behaviour from you. I wonder why he thinks that behaviour he wouldn't tolerate in you, is permissible for him? That might be because of a sense of entitlement that has never been challenged and it might be something deep-rooted about his attitudes to women and the roles men and women play in relationships.
For you to regain the intimacy and connection you once had, you've got to stop feeling that certain subjects are off-limits for fear of being regarded as a jealous harridan - and he has got to listen and try to walk in your shoes; the empathy I was referring to earlier. Perhaps he does see you as indecisive and non-assertive and maybe you have been like that a bit. Perhaps that's because of this power dynamic I was referring to - you have acceded to his wishes for too long. That's going to have to change if you're going to get your relationship on a more equal footing.
I think one of the most significant shifts that could happen here is for you to stop feeling scared of him and for him to start feeling scared at the prospect of losing you.
This is what got you results last time, even if you had to do it in the dark and without looking at him (I know I keep returning to that, but I think it's significant).
When you look again at what I charted as indisputable, what I want you to see is that feeling threatened was perfectly legitimate. If you get Not Just Friends (please, please do!) you will see that reinforced over and over again. Whether he agrees or not is irrelevant, but if he would also feel threatened if the situation were reversed, he's got nowhere to go with that argument.
It would be enormously helpful if you make headway in restoring the power balance, if you could get him to read that book too at some stage. It makes such enormous sense. I've never known anyone who is fully invested in their marriage disagree with its message, that the only safe friends are ones who wish the marriage well and aren't hoping that one of the marriage partners will one day sleep with them. Anyone who doesn't feel threatened by their partner having a new friendship with someone for whom there is a mutual attraction, is not invested in their marriage. In fact, they've already got one foot out of the door....what you've felt all along was entirely normal for a woman who loves deeply and honestly. If you hadn't felt threatened by this in fact, he would be entitled to question your true feelings for him.
Please never again feel scared about admitting that you love him so deeply that you cannot be complacent about him. Never feel scared about asserting your right to respect and dignity - and the right to have your fears taken seriously and not belittled or scorned.