Sheila Johnson, entrepreneur, philanthropist and co-founder of Black Entertainment Television, opens up about her life journey in her new memoir, "Walk Through Fire: A Memoir of Love, Loss, and Triumph."

The book, out Tuesday, delves into Johnson's experiences, from her achievements to the personal hardships she has faced, giving readers an intimate look into her life. The memoir sheds light on Johnson's early determination to become independent, driven by her mother's emotional collapse when her father left their family. Johnson said her commitment to financial and emotional security was a theme that shaped her life.

Johnson revealed that writing her memoir was a form of therapy and that she's been battling post-traumatic stress.

"I've been through a lot," she told "CBS Mornings" on Monday. "It's been a tough journey."

Her book is published by Simon & Schuster, which is a division of CBS News' parent company Paramount Global.

Johnson, along with her then-husband Robert Johnson, made history in 1980 when they launched BET, a cable channel that is now owned by Paramount Global. BET sold for nearly $3 billion in 2001, catapulting Johnson into the history books as the nation's first Black female billionaire.

But it also came with some hard times. Johnson has accused her husband of infidelity and emotional abuse and said she used to see herself as a failure. Her former husband told her she was a failure and "wasn't worth anything," she said. 

"I was young enough, and I really did believe him because I put him up on a pedestal. I really did. And I thought that everything he said was right, and I had to keep fighting through that. That's what upset me more than anything," Johnson said.

CBS News has reached out to Robert Johnson for comment about her book.

Now Sheila Johnson said she urges young women not to get into relationships without first knowing themselves.

"I tell this to many young girls: do not get involved in a relationship until you know who you are. I didn't know who I was. You know, I was planning my life as I was going along," she said. 

Johnson, an accomplished violinist, said the arts kept her grounded. 

Johnson has also pioneered shows like "Teen Summit" and now serves as the CEO of Salamander Hotels and Resorts and co-owns three professional sports teams in Washington, D.C. 

As for who she is today, she said, "I'm a very powerful entrepreneur."