Even now, just a few days before the release of her memoir, In Pieces, Sally Field wasn’t sure she wanted it published. She felt a similar ambivalence throughout the six or so years she spent working on it and wasn’t confident, from the moment she composed its first words, that anyone would want to read what she wrote.

“I didn’t know I had a voice,” she said gently, in a recent conversation.

Still, Field felt compelled to say something when, in 2012, she addressed the Women and Power conference at the Omega Institute in Rhinebeck, New York.

Rather than make some anodyne opening remarks, she shared a complicated reflection about her pursuit of the Mary Todd Lincoln role in the Steven Spielberg film Lincoln and about her own mother, who had died of cancer in 2011.

Soon after she learned the Lincoln part was hers, she made dinner for her mother. Then she opened up to her about how Field had been sexually abused as a child by her stepfather.

It had been difficult for her mother to hear that it was not a single act but actually a series of offences from throughout Field’s adolescence. But that next morning, her mother, even in her declining health, assured her that she would not be alone any longer in her pain.

Recalling the experience of giving this speech, Field said: “I was shaking all over to do it. But I felt strengthened by that faceless mass of unknown people. When I laid it out there, I felt them giving me something back.”

Seated here in her airy Pacific Palisades home one afternoon in late August, Field, 71, carries herself with quiet poise. She is not by nature a confessional person; despite the visibility she has gained from a decades-long acting career – she has won three Emmys and two Oscars, and starred in films such as Norma Rae, Steel Magnolias and Forrest Gump – she finds it easier to speak through her outspoken characters than put herself on display.

In Pieces, which Grand Central Publishing will release on 18 September, is hardly a traditional showbiz autobiography, though it does delve into some of Field’s famous roles and relationships with celebrity co-stars such as the late Burt Reynolds, and it recounts how she raised three sons through two marriages that ended in divorce.

The life that Field reveals over the course of In Pieces is one that has been darkened by abuses and cruelties that are frustratingly commonplace for women, both inside and out of the entertainment industry.

The book also tells a story illuminated by its author’s abundant grace and dignity, and her authentic desire to plumb the depths of her feelings, a yearning that she said overwhelmed her reticent tendencies.

“Something was growing in me, this urgency that felt gangrenous, and I couldn’t locate it,” Field says. “I could hardly breathe and I couldn’t settle down.”

She says compulsion became more acute after the death of her mother, Margaret, who raised the Field family in southern California and acted in movies like The Man From Planet X.

After Margaret Field filed for divorce from Sally’s father, Richard, in 1951, she got remarried in 1952 to Jock Mahoney, a stuntman and actor (Tarzan Goes to India) known by the nickname Jocko.

Field with Burt Reynolds in ‘Smokey and the Bandit’, 1977 (Rex)

Sally Field writes of Mahoney in her memoir: “It would have been so much easier if I’d only felt one thing, if Jocko had been nothing but cruel and frightening. But he wasn’t. He could be magical, the Pied Piper with our family as his entranced followers.”

He also frequently summoned Field to his bedroom alone. “I knew,” Field writes. “I felt both a child, helpless, and not a child. Powerful. This was power. And I owned it. But I wanted to be a child – and yet.” Field said her stepfather’s abuse of her stopped after she turned 14. Her mother divorced Mahoney in 1968, and he died in 1989.

Field’s sexual awakening in her late teens, a period in which she said she felt she was “breaking out of my own brain”, was followed by a secret abortion in Tijuana when she was 17. Then came her astonishing professional ascent on TV’s Gidget and The Flying Nun, and the end of any sense of normalcy in her life. “I was no longer a member of the club anymore,” Field writes. “The Human Club. I was a celebrity.”

Feeling unable to fully share her experiences with others, Field sought an outlet in her acting, and in roles like Sybil (the 1976 TV miniseries that cast her as a woman with multiple-personality disorder) and Norma Rae (the 1979 feature in which she played a budding labour activist in a cotton mill), which allowed her to negotiate long-held frustrations.

Playing parts like these, Field says, “I was able to feel something I didn’t feel before. I heard my voice. And I wondered what would have happened if I hadn’t. How long would it have taken me to feel that I had a right to be outraged?”

She had ample reason to feel this way. Field writes of an encounter in 1968 with the singer-songwriter Jimmy Webb, when, after they both smoked a joint filled with hash, she woke up to find Webb “on top of me, grinding away to another melody”.

Despite the visibility Sally Field has gained from a decades-long acting career, she finds it easier to speak through her outspoken characters than put herself on display.

In an emailed response, Webb says: “I am being asked to respond to a passage in a book that the publishers refuse to let me read, even at my lawyer’s request, so all I can do is recount my memories of dating Sally in the swingin’ 1960s. Sally and I were young, successful stars in Hollywood. We dated and did what 22-year-olds did in the late Sixties – we hung out, we smoked pot, we had sex.

“I have great memories of our times together and great respect for Sally – so much respect that I didn’t write about her in my book because I didn’t want to tarnish her Gidget image with our stories of drugs and sex.”

When she auditioned for her role in the 1976 feature Stay Hungry, Field writes, its director, Bob Rafelson, had one final stipulation: “I can’t hire anyone who doesn’t kiss good enough.”

“So I kissed him,” she writes. “It must have been good enough.” Field told me that at this time in her life, “I was the sole support for my family, and I didn’t see that I had any direction but down, unless I could get out of this spot that I was in.”

Reached by phone at his home in Colorado, Rafelson says: “It’s totally untrue. That’s the first I’ve ever heard of this. I didn’t make anybody kiss me in order to get any part.”

Field devotes several pages of In Pieces to Reynolds, her former lover and co-star in films like Smokey and the Bandit and Hooper. Though celebrity periodicals often portrayed them as a blissful, well-matched pair, Field told me their time together was “confusing and complicated, and not without loving and caring, but really complicated and hurtful to me.”

She characterises Reynolds in the book as swaggering and charismatic, and their connection as immediate and intense. She also portrays him as controlling of her, only able to accept certain aspects of her life and personality while uninterested in or disapproving of others.

Field writes that Reynolds used Percodan, Valium and barbiturates during the making of Smokey, and sometimes received mysterious injections to his chest. She recounts how she organised a surreptitious examination for him at the Miami Heart Institute, which came back all clear, but that Reynolds refused her urging to seek therapy for his stress and anxiety, dismissing it as “self-delusional poppycock.”

Field’s assessment now is that, in her romance with Reynolds, she was trying to recreate a version of her relationship with her stepfather.

“I was somehow exorcising something that needed to be exorcised,” she says. “I was trying to make it work this time.”

In a telephone conversation after Reynolds’s death, Field says she is “flooded with feelings and nostalgia” about him. She expresses relief that Reynolds would never read her memoir or learn what she wrote about him.

“This would hurt him,” she says. “I felt glad that he wasn’t going to read it, he wasn’t going to be asked about it, and he wasn’t going to have to defend himself or lash out, which he probably would have. I did not want to hurt him any further.”

Even as she committed herself emotionally to the idea of writing about her life, Field was not confident she had the literary ability to complete the task.

“I know how hard it is to learn a new craft – it takes many a sore ride in the saddle,” she says. “You get thrown around and beat up and get back on that animal.

“It was never a matter of making myself write. It was a matter of being terribly irritated when anything else got in the way.”

Though some members of her family knew she was working on the book – in addition to her three grown sons, Field has an older brother and a younger half-sister – she did not start sharing its manuscript with them until earlier this year, and with apprehension.

Sam Greisman, the youngest of Field’s sons, says he was broadly aware that she had been abused by her stepfather, and that he knew she’d had “a childhood where no one was allowed to talk about anything”.

Greisman, a 30-year-old filmmaker, says that when he was growing up, Field “was already a woman with a very established career. I never felt like I saw her unsure how to handle something. She always seemed so together.”

Reading In Pieces and seeing the full breadth of his mother’s life has given him a greater appreciation for her, he says. “To see her as someone who grew up confused and made mistakes and went through these traumas, it made me feel more connected to her.”

Now comes the part when Field will share her stories with a mass audience, and she could hardly predict how her readership will receive them, or how she might receive her readership.

Though the frankness of In Pieces might resonate in a #MeToo era, Field is reluctant to offer up her book as a paradigm for others who might want to disclose their survival narratives.

“People should tell whatever story they want to tell,” she says. “This is just my story and it happened the way it happened.” Outrage at the abuses that others have suffered is warranted, she says, but it “is the first part of it, it’s not the fix. Outrage has to come first and it can’t just be quieted and go away.”

What Field hears loudest right now, more persistently than any other reaction that In Pieces might elicit, is the voice in her own head, still questioning herself over the book. “Can I just pull this back?” she says. “Can I change my mind? Can I say, never mind?”

She adds, resolutely: “But I didn’t.”

Sally Field’s memoir In Pieces is published on Tuesday