Rousey, 30, suffered a devastating first-round loss to Nunes in the main event of UFC 207 in December 2016.
The former UFC women’s bantamweight champion was stopped by a vicious onslaught of punches a mere 48 seconds into her eagerly-anticipated comeback fight.
The Olympic bronze medallist went into hiding after that night at the T-Mobile Arena, a decision which was slammed by many.
According to Rousey, defeat to Nunes left her an emotional wreck and sapped the little will she had left to compete.
“I remember my last fight, walking away thinking God hates me,” she said in a video to promote her WWE Raw debut. “I had nothing left in me.
“My husband (UFC heavyweight Travis Browne) is amazing, and he really brought me out of some tough times.
“He would just look at me and say, ‘You’re not only this. You’re more than just a fighter.’
“And that’s not a bad thing, that’s not something I should be ashamed of. It’s something I should embrace and showcase to the world, and that’s why I’m here.”
Defeat to Nunes paved the way for Rousey to swap the UFC for the WWE, a decision she’s delighted to have made.
“I’m not afraid to care anymore,” she added. “I needed to be miserable then to be truly happy now.
“It’s all led to this, and I didn’t even realise that I’ve always been on this path.”
Rousey’s comments on her loss to Nunes come less than a week after she closed the door on a return to mixed martial arts.
“I don’t know,” Rousey told Ellen DeGeneres when asked if she’d ever return to the UFC.
“I think it’s just as likely as me going back to another Olympics for judo.
“No one demanded a written resignation from me for judo and I don’t really think the same thing is necessary for fighting.
“I’m just doing what I enjoy and WWE is what I enjoy right now.”