Holy cow I'm so sorry this has happened to you. What a crappy place to be.
I am not one to give advice about what you should or shouldn't do. I think nobody knows your situation like you do. There are trends and patterns that we see here a lot, but ultimately, there is a not a cookie cutter answer for every situation.
AGain, I'm so sorry you are here. I'm interested in knowing what YOU want. Do you want to try to stay with him? Do you want to stay together but not be married? Do you want to get out of Dodge? All of these are valid. All of them have risks. If you stay with him, he might cheat again. (many people say that the best indicator of future behavior is past behavior). If you run away, you might miss out on a long happy marriage that might have been. You might wonder what might have been. I am not here to tell you which road you should take.
IF you are wanting to try to let him figure out his shit and try to work this out with him as your husband, is staying at your awesome job an option?
When I first found out about my XW's affairs, I was a wreck. I couldn't eat. I couldn't sleep. I felt like my hair was on fire all the time. (figuratively) I was anxious and felt like I had no idea what end was up. And I got a some good advice about taking care of myself. And that advice I will share:
Make sure you're getting water and some food in you every day. Especially water. FOr me, walking and other exercise was very helpful. Endorphins and all that. I don't drink or smoke, so those were not temptations, but I hear they make things worse. I looked for things that "give me life." I paid extra attention to what I thought I might need. (because I haven't always been good about that.) Be kind to yourself. And do whatever it takes to get whatever kind of support you need.
You don't have to blow him up and tell the world. But you can if you want to.
You don't have to tell his family. But you can if you want to.
You don't have to demand a polygraph. Or a timeline or "all" the answers. You can if you want to. (You can try. He might not cooperate, in which case, it's good to decide what will happen if he doesn't.)
You don't have to forgive him. Or hate him. YOu can if you want.
You don't have to run. You can if you want.
You have choices. And whatever you decide for today, can be for just today. And new choices tomorrow.
We're with you. And we support you.