"I've never really been in such a healthy relationship. I'm like, 'Something's going to go wrong. Is he going to trip me or something?'" the star said during a panel discussion at Maria Shriver's Women's Conference in Long Beach, Calif., on Tuesday.
"I'm waiting for something bad to happen," she said, "but then I have realized that I actually do deserve an understanding relationship."
Simpson, 30, who calls her beau of six months "a hottie", said Johnson "has been an inspiration. He really knows himself."
The same can be said of Simpson: More than four years since her divorce from Nick Lachey in 2006, the singer/actress/entrepreneur has not only found love, but also a new level of hard-fought confidence.
Who helped Simpson find her footing after the split? Her little sister Ashlee Simpson-Wentz.
"My sister and I, through my divorce, became so much closer than we'd ever been growing up," Simpson said during the panel discussion, billed as It's Time to Learn How to Build Self-Esteem and Leadership in Young Women and hosted by Dove. "She would always give me music to listen to to get me through."
The sisters often cranked up the Sister Act soundtrack and Lauryn Hill's "His Eyes on a Sparrow" as well as Patty Griffin's "Let Him Fly", she said. "'Fly' is about that moment where you learn to fly and live on your own and that's what I was doing through my divorce, learning to live on my own."
While Simpson cherishes being an aunt to Ashlee's son, Bronx, she said, "I always thought I would have children before her since I was married before her."
But Simpson has taken away life lessons from her hard times. "Another thing that can strip you of your self-esteem is a divorce and you have to start back over at the beginning and find out who you are all over again," she said.
These days, an enlightened Simpson is excited about what her future might hold.
"I was on a little bit of a detour but I finally went back on the path that I was supposed to be on," she said, "and I grew from that experience and it made me a better lover, and hopefully a better wife one day and an incredible mother someday."
Eric Johnson, take note.