I f I were a betting man, I'd be willing to put up a few quid on the idea, that your W is polishing someone else's bishop. And is using your "transgression" to justify the divorce and to shame you into giving in to all her demands.
Sorry to be blunt, but I call it as I see it.
I'm not so sure. She is so adamant that she would never cheat, full stop. However she did say once, "how should we sort this out? Should I cheat on someone?!" Not sure if she was joking. Anyway, it'd be a totally different scenario, seeing as my infidelity is entirely online (no that being only online justifies it and makes it less hurtful to her, I get that).
I don't think she's seeing someone else. She would say "If you met someone else and wanted to be with them, I'd rather you told me instead of keeping it from me." Even when this didn't happen, she'd bring it up when things were fine between us, before and after marriage. I always thought that was weird. She definitely has insecurity issues that an IC should be addressing, but as I say, she refuses to take it.
The timing, the 3 week silence and the unusual sex drive right before the split up is a tell tale sign for me.
One other thing is a certainty also: No amount of pleading, ass kissing, shoe lickin', groveling puppy eyed behavior will bring her back. You've apologized enough. Even if she had a miraculous change of heart and decides to come back, would you be willing to live the rest of your life with your W dangling your "transgression" over your head the whole time?
You have to forgive yourself. Yes you F'd up, so what. We all f'u from time to time. On the scale of f'ups (the scale going from 1 (insignificant) to 10 (deffo marriage wrecker)), your transgression measures 2, maybe 3 on the $hitometer. On the end of the day, if your wife wants out, you have to let her go. If she decides to come back, you have a chance then, but if she decides to stay away, she was never your to begin with...