Oprah Winfrey is getting emotional over what her friendship with her best friend, Gayle King, has meant to her all these years. The media mogul recently appeared on The Drew Barrymore Show, airing Friday on CBS, and fought back tears as she talked about how Gayle has been there for her through everything.

Oprah discussed her new book, What Happened to You?: Conversations on Trauma, Resilience, and Healing, alongside her co-author, neuroscientist Dr. Bruce D. Perry. The 67-year-old talk show legend shared that during her years hosting The Oprah Winfrey Show, she never underwent therapy.

“I never had therapy — I had all my therapy on television in front of all of y’all — and what I realized … is that Gayle was my regulation,” she says. “It makes me want to cry now thinking about it. Every night after the show, I would come home, and I would have these sessions with Gayle where we talked about what happened on the show, or what didn’t happen on the show, and that was the way I kind of regulated myself. So, I would talk to Gayle before bed, and then I would be calmer.”

Oprah admits that she only recently came to that realization.

“And it wasn’t until I not only was co-authoring the book but actually went back and re-read the book that I realized, ‘Oh Gayle was what I used for my sense of regulation,’ and is still the person in my life,” she notes. “I have probably three people in my life who are going to tell me the truth no matter what.”

Oprah has recently been opening up about traumatic moments during her childhood when she was raised by her grandparents. During her appearance on The Dr. Oz Show, she recounted a terrifying moment that is linked to her feeling unsafe while sleeping. Watch the video below for more.