Jessica Simpson is sharing some secrets behind building her billion-dollar fashion empire.

The fashion designer, singer, actress, and best-selling author, 42, appeared on a recent installment of American Express' Business Class: Office Hours to answer questions and give advice to other aspiring entrepreneurs — and to talk about her own journey of self-discovery and success. 

According to Simpson, her brand identity came into existence following her portrayal of "Daisy" on The Dukes of Hazzard and her divorce from Nick Lachey. 

"2005 was a major life change for me," she shared during Friday's Instagram Live. "I mean it started with a big personal decision of divorce."

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"That was a work thing because of a TV show and always being on tour, but it was also, for me, personal growth. I was coming into my own as a woman, and I feel like with Dukes of Hazzard, and the success of that and really channeling Daisy, I learned a lot about myself."

Although her marriage to Lachey ended, and therefore so did the show, Simpson says that it was fan's reactions to her on Newlyweds that inspired her fashion sense and the branding of the Jessica Simpson Collection. 

"People had sat with me on the couch and been watching me in my normal everyday life. It's nice to be glamorous but it's also good to see what's behind the glamor," Jessica shared. "And if you can make a t-shirt glamorous, that's really just who I am — the DNA of fashion for me. And so we decided to do the Jessica Simpson collection."

She continued, "I was just like, 'Wow — People are really liking just me for myself and how cool would that be to have a brand that is like that.'" 

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Simpson has faced setbacks along the way, but the mother-of-three says her passion for the company and her brand drowns out the noise. "People have slammed doors in my face. They said I'm too dumb, you know, 'What's her IQ?', stuff like that," she began. "But I just feel like purpose outrides insecurities."

Confidence and authenticity also play roles. When asked about what has made her business so successful, Simpson said, "We win when we are authentic to who we are and if we believe in that power and have confidence in that power."