Birddog65-
Sorry to hear about your situation. Been there, done that. Reading the responses here was like re-living the entire thing all over again. 95% of the responses are spot on though, and you need to pay attention.
Take some time off work, starting this morning, for as long as you need. You will need several days minimum. While it's tempting to immerse yourself in work so you dont have to think about things, it will be the most costly week you have ever spent at work.
GET A LAWYER NOW ! ASAP! NOW, COMPRENDE?! Pick the 5 best lawyers in town and set up an appt. Initial consults are usually free, or minimum charge. By the time you have talked all 5, you will know several things. You will know which one you like/trust. you will have been given some good advice. You will likely have figured out who her lawyer/law firm is as they will not be able to talk to you. Likewise , she will not be able to use the lawyers you have talked to, assuming she doesn't already have one (she's had a lot of time on her hands, 98% chance she has one already).
Get your guns, all of them, out of the house. Pick a trusted friend that you are absolutely sure could no how, no way be diddling your wife, and "sell" them to him. You have bills to pay you know, and you definitely do not want your wife telling her lawyer or a judge that she "feels threatened". The atmosphere at YOUR house is about to get emotional and adversarial, if it hasn't already.
Speaking of which, DO NOT LEAVE THE HOUSE UNTIL A JUDGE TELLS YOU TO. Grab a sleeping bag and hit the couch in the basement. Treat your wife as nicely as you can , don't argue, don't plead, don't be disagreeable, but DON'T LEAVE. It's your house and you have a right to be there, as long as you don't pose any threat, real or perceived or even imaginary to your wife or kids.
Get your self to the bank(s) and close or split all joint accts. as well as credit cards. Get a couple of your own, convert balances to cash and "do something with it". You'll figure it out. You'll need access to it, but no record of it later. You've got a lot of unexpected expenses right now, remember?

Now for the rest of it.
Don't try to figure it out. Chances are very high that she doesn't want you to be able to. It will just make your head hurt worse.
Don't post on social media until after it's final. No Campfire, no facebook, no twitter, nothing. You can read if you like, but do not air your dirty laundry. It's not like we wouldn't be happy to power wash it for you, but it's very likely that any good lawyer is going to read and/or monitor anything you say or do. If you have to blow off steam, pay a counselor.

Always, ALWAYS take the high road. As has already been said,be the man you want your children to think you are, always. As a businessman, you know what this means, and how to do it, no matter how difficult it may seem at the time.

This is a temporary condition. How you conduct yourself will have a lasting/ permanent effect on your children though. You need to pay attention to the long game by playing the short game very very well.

This truly is a temporary condition. On the day you were born and on every day before and after, there were more women born than men. Someday when this is past and you get your feet back under you and your head screwed on, you will find one that truly does appreciate you, and you'll wonder why or how you ever ended up where you were.

If it does turn out that you defy all the odds, your wife suddenly pulls her head out and takes a gulp of fresh air, etc.,
it does not change one word of what I posted above. Do not sit around and hope for that flash of enlightenment on her part.

Good luck and check back in when the dust settles.