Kerry Washington in Los Angeles in June.
CNN  — 

Kerry Washington is sharing a piece of her family history.

In an interview with People published Sunday, Washington revealed she learned in 2018 that her dad, Earl Washington, is not her biological father – something the “Scandal” star says “really turned my world upside down.”

“When I got this information, I was like, ‘Oh. I now know my story,’” Washington said. “I didn’t know what my story was.”

The actress and advocate is now sharing that story in her memoir, “Thicker Than Water,” wherein she documents how learning about her actual ancestry ultimately inspired her to write the book.

According to People, Washington’s parents told her about her biological father in 2018 after she informed them she was planning to appear on PBS’s “Finding Your Roots,” a program that features celebrities learning about their ancestry via DNA testing.

Instead of finding out on TV, her parents ended up telling her in private, revealing to Washington for the first time that they had turned to an anonymous donor to help them conceive after facing fertility issues.

“Taking this deep dive into our family history made me put myself in their shoes and think about the things that they’ve had to navigate and what they’ve been through and what they’ve sacrificed. And it really made me feel closer to them,” Washington said.

She added that she “started to have so much more love and compassion and understanding for my parents.”

“Thicker Than Water” chronicles Washington’s upbringing and “gives readers an intimate view into both her public and private worlds,” according to a news release from the memoir’s publisher, Little, Brown Spark.

“She reveals for the very first time how she faced a series of challenges and setbacks, effectively hid childhood traumas, met extraordinary mentors, managed to grow her career, and crossed the threshold into stardom and political advocacy, ultimately discovering her truest self and, with it, a deeper sense of belonging,” the release read.

“Thicker Than Water” will be released Tuesday.