OP. I hope I'm generally not insensitive to those who are hurting. I don't want to rub salt in the wounds of people who are already suffering and are reaching out in despair for help. There are a lot of these on this site.
In your case, in the gentlest possible sense, you need to give yourself a shake. You posted the same question two months ago, then again a month ago (I don't recall any user names from the time but I certainly recall the content). On both occasions people took time out of their day, in good faith, to reply to you. And the overwhelming majority of them were telling you the same thing.
That's all very well. There's nothing compelling you to take advice from mere strangers online. It's your life and what you do is up to you. But ignoring that advice and then running back asking for the same advice - twice - is not reasonable. Nor is it rational. It also risks alienating those who have tried in all good faith to help you.
You've heard that old phrase that the definition of madness is doing the same thing and expecting a different result? I'm afraid the same thing applies to your 'partner', and I use that word in the loosest possible sense. You're running around on a treadmill to nowhere, you're obviously driving yourself mad trying to find answers that will not be forthcoming, and it's only resulting in taking you back to the place where you started. We're four months down the line and nothing has changed. I think it's now safe to assume that it never will. This must be causing you no end of emotional torment. Why wouldn't you want that to stop?
The longer you continue in this dead-end relationship, the more you'll exhaust yourself on that endless treadmill. Is this the way you want to continue living? As for your continual protestations that you're convinced he isn't attracted to her: you're completely in denial. Otherwise why are you continuing to post on here - months later?
What an exhausting, untenable situation. Be kinder to yourself OP and set yourself free.