There is no good reason to leave most marriages. What comes out of her mouth may not be BS, but it certainly isn't justification for her decisions. And while you can apologize for hurting her and validate the pain she feels, you don't need to go so far as to play along with the idea that she is right to think that divorce is a reasonable choice for her to make.

As for not getting it, I'm glad you don't get it. The only way you would get it is if you believed that it was ok to get divorced because you got into an argument. Given the choice between understanding her and having values I'd be ok living in the dark on this one.

When it comes to fear of your single life, that is totally sensible. You have incurred a tremendous loss. Something so primal it is hard to put into words. The loss of your family, your wife, and your innocence in the way that relationships work. It isn't distorted thinking to realize that your future will be different than it would have been had she made other choices, that you will miss having a life partner, that you will be saddened by this loss for years and possibly forever to some degree. Of course you're going to rebuild your life and find ways to honor and appreciate what you still have, but this doesn't mean it isn't the darkest hour in your life. Again, I'm glad you feel this way, I've said it before and I'll say it again, I'd rather you felt this way than to be a sociopath that just shrugs it off and feels that a marriage is optional, disposable, and replaceable.

At this point there's not much to do. She's leaving so your behavior won't impact her much. You're going to feel how you feel, which will be more down than up for a while. So now it's just a matter of what you choose to invest in for the future. Nothing you can do (or should do at least) will make you feel better right now. But the things you do now may make you feel better sooner than otherwise, and give you some tools to make your life better in the future as well.

Looking back in two years and retelling the story to your friends of how you handled this situation, what would you like to be able to say you did?

Me:38 XW:38
T:11 years M:8 years
Kids: S14, D11, D7
BD/Move out day: 6/17/14, D final Dec 15