I'm sorry. Really. I know how traumatic and sucky this is. Many of us do.
However, please believe me when I say that you are behaving in a way I wish I had when I found out about the affair. And many others come here and cannot defend themselves in the way you have-read other posts! We give this advice open handedly here and it often falls on deaf ears because some folks aren't ready to let go of their alcoholic. They still want to hold on and keep trying to work with or change their A's. They're still stuck in their own addiction to their A. Myself included in some ways.
The course of action you're taking is sane. Careful and mature. We "make you out to be strong," because we've seen hundreds of other folks come here, ask for advice and stay in their abusive situation. I"m learning to sthu when that happens and let those folks walk their own path.
I know others have done the same with me. So it's inspiring and beautiful to see someone come here and find the escape hatch right away. We see the bigger picture, and so do you, despite the grueling pain of initial discovery that your H is having an affair.
Yes, he's cold and mean. Be prepared for him to either attack you or plead for another chance when he's served. He'll blameshift and make it all your fault, or try to convince you he'll change-he may even do both of those things in the same conversation. It's amazing.
Can you get yourself into therapy too? Or go to Alanon meetings? We may all be high-fiving you, but this situation is all consuming and exhausting.
Thank you for keeping us updated. I hope you're hanging out with your little guy too, now there's some healing power.