I am so sorry to hear this. Now you know for sure and nothing has really changed because he's still going to be out there as a confused puppy. Let him go to figure things out.
Now, it is very important that you take care of YOU. Find a pillow and beat the stuffings out of it. Find something physical to do to help you relieve some of that stress and grief. You have to take care of yourself.
Shining is absolutely correct, you are them most important person right now and they are not. Don't worry about him because he's a grown man and yes, this is his mess to deal with. Now, you and your children will need to figure out how to move forward w/this news.
Again, I am very sorry to hear this news.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.