Maria Shriver Details Breakdown After 'Brutal' Arnold Schwarzenegger Divorce: 'I Was Terrified'

In a PEOPLE's excerpt from her upcoming memoir, I Am Maria, the journalist opened up about the "brutal" split from her husband of 25 years following the revelation of his affair.

Shriver, 69, filed for divorce in July 2011 after Schwarzenegger publicly revealed that he had an affair and secretly fathered a child with the family's housekeeper. (Their divorce was finalized in December 2021.)

In her book, Shriver called the end of her marriage a "devastating, life-altering blow."

"It broke my heart, it broke my spirit, it broke what was left of me," she continued, adding, "Without my marriage, my parents, a job -- the dam of my lifelong capital-D Denial just blew apart."

"I was consumed with grief and wracked with confusion, anger, fear, sadness, and anxiety. I was unsure now of who I was, where I belonged," Shriver recalled. "Honestly, it was brutal, and I was terrified."

The mom of four reflected on the moment she broke down in a hotel room over the dissolution of her marriage.

"As I sat on my hotel room floor in the dark, alone with tears streaming down my face, I thought to myself: Maria, this doesn’t have to be the end of you," she wrote.

Shriver noted that she didn't want to "bore and exhaust you with the details of my self-pity party" and would "spare you a litany of all my trips to various therapists, healers, shamans, and psychics," but she did recall how she visited a cloistered convent -- and what she learned.

"At the end of my stay there, Mother Dolores took me aside, and in what once again felt like a scene right out of The Sound of Music, said to me, 'Maria. I understand that you like it here very much. But if you're thinking you can come live with us, let me tell you, you can’t. Our cut-off age is fifty, and you’re fifty-five!'" Shriver wrote.

"She said, 'I think what you’re really looking for, my child, is permission to leave your marriage, to be Maria,'" she continued. "She hugged me, and then we both wept."

As shown in the excerpt, Shriver also praised how she and Schwarzenegger's children -- Katherine, 35, Christina, 33, Patrick, 31, and Christopher, 27 -- navigated their parents' split in the public eye.

"Now, much has been written about the end of my marriage, and frankly I don’t feel like I need or want to discuss it here, or anywhere," she wrote.

"That said, I do want to take a moment to acknowledge the grace, valor, and courage my children exhibited," she added. "Everything about their world and the sanctity of their home got uprooted in an instant."

I Am Maria: My Reflections and Poems on Heartbreak, Healing, and Finding Your Way Home -- a collection of personal poems about grief, love, and healing -- is described as "a roadmap for anyone trying to shed the labels, layers, and armor that holds us back from creating a wildly authentic and meaningful life," according to Random House.

In her book, per PEOPLE's excerpt, Shriver said she wrote from a "deep place within."

"Through my poetry, I've found a woman who was terrified of not being able to live up to her family’s legacy -- scared of not being big enough, a good-enough daughter, sister, wife, mother, journalist," she shared, adding that she's "made lots of mistakes."

"One of them was tying my self-worth to my achievements," she said. Another big mistake was thinking that someone outside of me could guarantee my safety, my worth, and my peace."

"I've also had to come face to face with other misguided beliefs -- about aging, about being alone," she wrote. "I used to believe that if you didn’t have a partner, you must be unworthy and unloveable. I’ve learned that nothing could be further from the truth."

I Am Maria will be released on April 1. Pre-order it here.