tld-Just say what you did, walk away. If he follows you, you can always grab the kids and go grab a couple of groceries or go to the park. Show him that if he treats you that way, you'll leave. You can bring the kids with if you need to. No need to alarm them. "Oops, I forgot we need some milk/bread/whatever, come on guys, lets run to the store together. Then leave. That simple. You don't have to bring up OW.
It might take some time, but tld you need to find your strength and you will. And when you do, you'll feel powerful and less out of control and your life will change within this sitch.
Me:33 H:35 M: 12 years D-15 S-6 Bomb: 6-2013 OW: 11/2013 Kids and I moved out: 11/2013 when he continued to lie about affair Kids and I moved back in 12/2013 H moved out 2/2014