CIPA....I'm so sorry. I truly am. But take a few days. Think things through. I do believe you when you say you are done, but take this time for you and for your boys to really think all of this through carefully. You can always move forward...backward is much more difficult.
I'll be the Devil's Advocate....what if in the last two weeks she's called all of it off? What if she's now come to her senses and realizes what all of us know? That you're an amazing man, father and husband?
Take this slowly.
I'm not even sure you need to confront her if you make the decision to move foward with D. Just do it and when she asks tell her you know about the affair(s) and when she tries to question you tell her "The point of D is so we don't have to answer to each other anymore" and leave it at that.