My apologies for sounding harsh. I don't have much time right now, but I will write back later and try to explain my thoughts (whether they be right or wrong or crazy) in more depth. And perhaps I'll say something helpful... and perhaps not...
Honestly, I could sympathize and agree with everything you say (and believe me I'm completely on "your side"), but I don't think that would be helpful in giving you alternative perspectives or ideas that may help you save your marriage.
Okay.... I have a few moments...
You wrote about telling your wife: "if you spent half the effort on your family, that you do on OM, then we wouldn't be in this situation."
Even though that's true and a logical response on your part, to your wife it would sound like you were blaming her (even if it is her fault, this is not a way to convince anyone to stay in a marriage). That coupled with her thinking you've been spying on her R with OM, learning about his other relationships, etc... could feel quite controlling and manipulative to her.... like you're telling her that since OM is a scumbag (and yes, you and I know he is), she should forget him and work on the marriage.
Yes, she should do that. But when a spouse is angry and has filed for divorce, they will only see you as "the bad guy." They will only blame you. Everything gets twisted around. Convincing someone to stay in a marriage is not a matter of telling them, or even logic. You have to detach, try different things to see what works or doesn'tm and sell yourself like you would to ANY woman you might meet.
I know you are a good guy. You are here on this board and you want to keep your family together.... but keeping your marriage together and convincing your wife about this is a whole other matter.
I'll try to go over some more points and things that you asked me about when I have more time.
There is no arriving, ever. It is all a continual becoming.