Jana Kramer and husband Mike Caussin have long been downright candid about the triumphs and challenges of their relationship through the years. But we never quite heard about just how mad she really was about his infidelity in 2016.

“I smashed a bunch of stuff, and I wrote all over his wedding tux, a-hole,” Kramer admits during a new interview that aired Friday (Oct. 9) on the Dr. Oz Show. “I was mean, and I was angry, and I shamed him. I was rageful.”

Granted, the “I Got the Boy” hitmaker and actress was not only lashing out due to her own feelings about the situation, but also because she was then a mother of one looking to protect her little girl in every way.

“I come from a divorced family, and I love my daughter and my son so much, but at the time, my daughter (Jolie Rae),” says Kramer. “I was like, 'You don't get to break my family apart because of your selfish actions.' He was willing to fight. So I had someone that was willing to grow and to change and to be a better person.”

The journey to their healing following Caussin’s infidelity and treatment for sex addiction is documented in the couple’s new book The Good Fight: Wanting to Leave, Choosing to Stay, and the Powerful Practice for Loving Faithfully. And while promoting the book on the Dr. Oz Show, Kramer took viewers back to some of the couple’s worst days.

"I was in Orlando about to play a show and I started looking through the phone bill and I just saw a bunch of numbers that didn't add up," Kramer says about her earliest indications that her husband was unfaithful. "I remember being there with two of my other best friends at the time and I just was bawling."

"We had a little baby, and it was just one of those moments where you're just like, 'How? What? Why?'" she recalls. "All of these things, questions, but I had to zip it up, go on stage, and perform. Then when I got offstage, he started telling me things, that my whole world was just flipped upside down.”

The Dancing With the Stars alum recently shared pictures of Caussin’s baptism in February, a milestone that seemed to truly serve as a crucial moment in their relationship.

But make no mistake — addiction is something that can be tough to kick.

"You can't always explain it," Caussin says on the Dr. Oz Show. "You definitely can't justify it. I always try to mention that, especially with sex addiction. People look at it as a married man’s excuse, which I understand society hasn't caught up to the education around sex addiction. It's not an excuse, but it's an explanation of behaviors.”