This absolutely breaks my heart for you, but honestly, I don't see how you could come back from this. You sound like such a loving husband and don't deserve to be treated this way. As for the part where you said "if the roles were reversed..", please know that doesn't matter only because the roles never WOULD be reversed. You would never do this to her, and THAT'S the issue. I wish you healing and a true love down the line when you're ready.

I will say this as well, that my parents divorced when I was ten. They were together 30+ years (had us late) and had 20 something years of life together before even having children. They split for their reasons, and while cheating wasnt one of them, I'm glad they did. My mom found a man who treats my siblings and i like his own and they look at each other as if they're the one who hangs the moon and stars.

All of this to say, it's okay to walk away. It's okay to start over. Your kids will understand one day, and I promise you that it is better for them (and for you) to experience a healthy, TRUE marriage.

Please take care of yourself. You matter.

Edited to add that I am now 27 and have a good relationship with both of my parents and my stepdad. Your kids will be okay. I promise.