I want to say I'm sorry you are going through this, but I can't.
You seem to want to minimize your behavior. Heck you already started to on here.
a. It wasn't a one-time, one-night thing. It was over a 3 week period. That means you had time to plan, think and act on your feelings and time to reflect. But most importantly, you had time to BACK OUT. You didn't. b. You knew her stance on cheating from when you were married and yet you still cheated. You knew you could lose everything. You knew the rules going in, but you want her to changes that stance. Realistic? so in some ways, you do deserve to lose everything. c. You really need to see why you deserve to lose everything. Because if you don't think you do, you will never grasp why this hurts your W. d. You said you are willing to walk through h3ll to keep your marriage intact. Yet you couldn't keep it in your pants. doubts? yes e. It doesn't matter that you were faithful for 15 years or 20 years or 100 years, so stop using that some sort of crutch. You weren't being a good dad either as Knittedscarff pointed out. you put your needs above your family, wife and kids. f. You have a LONG road ahead. Like years (no matter if you stay together or not) Stop trying to make it shorter.
You only hope is to have your wife find the DB sight. It seems that the consensus here is to allow affairs to continue without any fallout for the cheating spouse.