In all likelihood, sadly, your marriage is over. The sooner you recognize and accept this, the sooner you can begin your life after divorce. The next months and years will be very painful, maybe the worst you've ever experienced. But it will get better with time if you take care of yourself and your children and keep focused on the present and the future but not the past. The advice of Michelle's that worked best for me was Get A Life. It did not save my marriage, but it saved me. And that was even better than my broken marriage.
Good luck and I'm sorry you are going through this.
"Now some kind of man, he can't do anything wrong. If I see him I'll tell him you're waiting." ---Lowell George