That is a reality that sometimes, there isn't anything we can do to save the marriage. But we can save OURSELVES! Everything you are learning in the DB book can help save your marriage, but it will surely put you in a better place to handle everything if it doesn't work out.
My ex did the same thing, she found someone else then told me she wanted out (I didn't know about him at the time). Nothing I did, or could have done, would have changed her mind. Do I know exactly what drove her to another man? No, and I never really will. But I do know that my actions, behaviors, and desicions played a key part in our marriages demise. Granted, that information didn't help me save my marriage, but it WILL help me make my next relationship better and stronger.
Don't spend too much time and effort trying to figure out why she left. Spend that time figuring out how to better yourself so you won't make the same mistakes again. Someday, you will be in another loving relationship (it might be with your W or with someone else). Don't you want to make sure that you have all the skills you need to make that one last?
