"I think he taught me a lot about inner beauty and confidence in myself," the singer, 25, tells Seventeen magazine in its September issue.
"I don't really feel pretty ever," she says. "Without makeup, I feel ugly. And so I would have to sleep with makeup on, or feel ugly and gross. He looks beyond all of that, which is such a win, because I've never felt that with anybody."
"He's in love with the person inside of me," she says, "and the outside of me is just a bonus."
And as the couple prepares to tie the knot, Perry stills remembers her initial attraction to Brand. "He changed my mind about him the moment I met him," she says. "I said, 'You are a better person than how you are portrayed.'"