“I don’t usually let my emotions get the best of me.” – Andi Dorfman

For the 29-year-old attorney from Atlanta, her future seemed as clear cut as The Bachelorette spoilers from Reality Steve every spring.

“I was 100 percent sure I’d spend my life with him,” she says of Josh Murray, her fiance and final rose recipient from her season on ABC.

It was not to be. The romance crumbled, and HARD.

Murray, 31, was jealous and emotionally abusive, she says, adding that during fights, he would sometimes call her a bitch or a whore.

Andi makes the shocking revelation in her new book It’s Not Okay, a hilarious spoof on her one-time suitor Juan Pablo Galavis’ catchphrase.

There’s nothing hilarious about their romance, though. She writes that it was “the most volatile and f–ked up relationship of my life.”

Dorfman recalls that after she made love to Nick Viall during her overnight date on The Bachelorette, she was full-on afraid to tell Murray.

Threatening that they would be “over” if she slept with Viall, she panicked and lied, eventually coming clean before Nick spilled the beans.

“He was devastated, angry and hurt, badly,” she adds, nothing that “I apologized profusely for lying” but he could not accept what she did.

“He seemed to struggle,” Andi writes, “over whether he was more upset by the fact that I had lied or that I’d had sex with another man.”

Several more apologies later, Dorfman says, it became clear the issue was about Nick – and that eventually torpedoed their engagement:

“That one sexual escapade would become a power play used by my fiancé to justify his mistrust in me. It would be an excuse to call me a whore.”

“And it would eventually lead to the demise of my engagement.”

The “two hotheads,” as Andi calls herself and Murray, clashed often over her desire to return to work and over her friendships with men.

In September 2014, just two months after their season finale proposal aired, Andi handed back Josh’s engagement ring after a fight.

Unable to sleep, she took a walk … and broke down.

“Alone in a random church, I cradled my head in my hands and began to sob. For the first time, I thought, I don’t think we’re going to make it.”

“But the thought scared me. If I wasn’t the happy fiancée, who was I? Back then, I wasn’t ready to answer that question.”

Soon enough, she was. They split in January 2015.

Murray responded to Us, “It saddens me and is very unfortunate that Andi has chosen to characterize me in such a negative way. I pray she finds peace.”