AceShowbiz - Jessica Simpson forced herself to endure an "extremely painful" confrontation with her childhood abuser in order to allow herself to heal from the trauma.

The "Irresistible" hitmaker goes public with her secret past as a sex abuse victim in her new memoir, "Open Book", revealing she was molested by the daughter of a family friend during sleepovers from the age of six to 12.

Her struggle to process the trauma eventually contributed to Simpson's downward spiral of substance abuse, which the mother-of-three only managed to conquer in late 2017, when she sought therapy to help her through the tough time.

And to aid her journey of healing, the 39-year-old had to face off with her attacker, who had also been abused as a child.

"I needed to confront my abuser," she tells People.com. "It was extremely painful and still is. It's still shocking. That little girl in me wanting to do the right thing, not knowing how to stand up for herself and not knowing how to stop it."

"I felt like a lot of who I am, the character of who I am, was built through the trials and the pain of abuse. I allowed it to happen, so I felt that I was as much of the abuser as the abused. So I was very shameful during that time, from six to 12 years old."

Simpson recalls eventually summoning up the courage to tell her parents, Baptist youth minister Joe and Tina Simpson, about the intimate incidents.

"I was a preacher's daughter," she shares on U.S. breakfast show "Today". "I was taught to be a virgin until I got married, and so I never wanted to share these sexual things that were happening because I didn't want to hurt anybody."

After breaking the news to her mum and dad, the issue was effectively ignored by her family, although her parents made sure their daughter was never subjected to the abuse again.

"They did the best that they could," Simpson says of how they dealt with the bombshell news. "That's a heavy thing to hear from your child ... They ignored it with their words, for sure, but they took action, and I never had to do the sleepovers again. I never had to go back."

"Open Book", in which the singer-turned-fashion mogul also addresses her failed marriage to Nick Lachey and struggle to deal with life in the spotlight as a teen, is released next week, February 04.