Jessica Simpson says she hit rock bottom on Halloween in 2017.

The singer, 39, in her new tell-all memoir "Open Book," writes how she was so "zoned out" from drinking that she couldn't help dress her kids in their costumes. Simpson admitted she had her first drink before a school assembly in the morning.

“It was 7:30 in the morning and I’d already had a drink,” she wrote. Later that day, she and her husband, Eric Johnson, were prepping for a Halloween party and he asked her if she could help get the kids ready.

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“I was terrified of letting them see me in that shape,” the fashion designer confessed in a book excerpt obtained by People magazine. “I am ashamed to say that I don’t know who got them into their costumes that night.”

That night, Simpson says, she took an Ambien and woke up late the next morning in an effort to avoid her kids.

“I slept in, afraid to see them, afraid I had failed them. I hid until they left, then drank.”

Simpson realized her lifestyle choices weren't healthy and told a few close friends she needed help.

"I need to stop. Something’s got to stop. And if it’s alcohol that’s doing this and making things worse, then I quit," she recalled.

"Giving up the alcohol was easy,” she added. “I was mad at that bottle. At how it allowed me to stay complacent and numb.”

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Simpson also starting therapy sessions twice a week and had the full support of her family and doctors.

"With work," she admitted. "I allowed myself to feel the traumas I'd been through."

She calls maintaining her sobriety “a continual gift.”

Simpson hopes by writing and talking about her life experiences, she can help others who are feeling lost.

"It's been a long hard deep emotional journey, one that I've come through the other side with pure happiness and fulfillment and acceptance of myself," she reflected. "I've used my pain and turned it into something that can be beautiful and hopefully inspiring to people."

And being sober has allowed the wife and mother to live a fuller and more present life.

“I had room for so many wonderful moments that I would have missed: sober for the first time ever in my studio and seeing Maxwell grab a guitar. Ace in pajamas he put on himself, proudly adding a sticker to his bedtime chart," she described.

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“There’s just no better gift,” Simpson added. “There’s no better gift I can give my kids, there’s no better gift I can give my husband. More importantly, there’s no better gift I can give myself.”

"Open Book" hits bookshelves on February 4.

If you or someone you know is struggling with addiction, please contact the SAMHSA substance abuse helpline at 1-800-662-HELP.