I'm so sorry that you had to find us, you'll be glad you did - the support is amazing.
I think you are in the very very early days of discovery, unless you unearth it he won't reveal anything. It's one of those "did you sleep with her after I found out", him: "yes but only after you found out and only once".
He doesn't seem very forthcoming with information does he?
You need to take care of yourself & not just the children, try and sip water, drink milkshakes or ensure, french fries can be easy, and rest when you can as sleep is nearly impossible.
There is a wealth of information in the Healing Library, you'll find a lot of great articles and such there.
Hang on honey - I think you've only scraped the first teensy layer of his lies and betrayal.
Don't excuse the A - everyone has stress but not everyone copes with it by having an A. Is he now NC (no contact)? Has he sent a NC text? He must come clean with EVERYTHING - trickle truth kills reconciliation. And every new revelation erases any hard work or healing done up until the new info. Read the following - it outlines what a truly remorseful spouse must and is willing to do to heal the BS.
Good luck - keep posting and reading. Know that you are not alone...WE get it and WE are here for you.
PS - YOU ARE NOT A FOOL!! None of us are - we all trusted our spouses - which is what's expected in a marriage. THEY are the fools for throwing their lives away and not valuing our love and trust.
Take some deep breaths. Drink water. Try to make sure you eat something each day.
You don't have to make any decisions today. Just concentrate on getting through each hour. Take the kids for a walk/to the park. Concentrate on them, and yourself.
IC or MC would be a good place to start. For both of you. Take your time, read here, there is tons that can help you. I'm sorry this has happened to you.
WH says marriage is over: May 15, 2009.
EA#2 July 20, 2009. Legally sep: Aug 16, 2009. DIVORCED!!!! Signed Nov 23, final Dec 24, 2010, adultery listed.
You are still in the early stages of discovery. Don't be surprised if more details come out until he's truly acting remorseful. In the mean time, read up in the healing library, and start working the 180. Make sure you take care of yourself - remember to eat, drink, and sleep when you can. And read and post here when you can.