My heart goes out to you. It will get easier.
It's so very hard to explain to someone that you were abused when your abuser seems like a nice, reasonable person. My mother was a totally different being when she was abusive to us. Her face would swell and get red. She spoke in a different voice. I'm sure her students or anyone who knew her would be so shocked to have seen her like that.
And it's very hard to describe certain kinds of abuse. I've written about my mother's abuse and even then, it doesn't always come across. The Arctic blast of a narcissist's rage that's like running into a wall of ice.
What anyone else thinks doesn't matter. You were there and you know what happened. I would maybe just slip away when the topic of marital discord comes up.