NVL, I'm sorry it's come to this painful turn for you.
Now is time to look out for your children. Most important, don't put them in a position where they are pressured to take sides with one parent or the other--and don't let your wife make them do that, either! Neither of you should be telling them details of why you're breaking up, about who did what to whom, or speak ill of the other parent (even if it is true, don't put children in the middle of adult disputes).
It may sound odd, but splitting up means you and your wife must now work together more than ever as parents. The worst part of a break-up is the effect on the children. Do what you can and must to take care of them, physically financially and emotionally. Expect to turn the other cheek many, many times--just remember that now you're doing it for the sake of your children, not for your wife.
It starts out rough, but trust those who have been there, with patience and time it will improve. Call out on the board when you need support.
GLT