‘Little House on the Prairie’ ‘s Karen Grassle on Her Sobriety, Tension with Costar Michael Landon

Karen Grassle, known for playing the beloved Caroline Ingalls, a.k.a. “Ma,” on Little House on the Prairie, is opening up about her journey to sobriety.

Grassle, 79, has penned a memoir, Bright Lights, Prairie Dust: Reflections on Life, Loss, and Love from Little House’s Ma — a natural continuation of the journals she has been keeping since age 13 as a way to cope with growing up with an alcoholic father, she tells PEOPLE.

In the book, set for a Nov. 16 release, the actress details her own struggles with alcoholism as well as her “up and down” relationship with Little House costar and boss Michael Landon, who played Caroline’s husband Charles.

Speaking with PEOPLE, Grassle says she made the decision to stop drinking in 1977, after two incidents that helped her realize she had a problem. The first was when she organized a luncheon for her costars on set and enjoyed a glass of wine — the “only time” she ever drank at work.

“After we went back to work, I couldn’t stop thinking about that bottle of wine,” she recalls. “And I just was like ‘What is wrong?’ I went outside, I went to the bathroom, I had mouthwash, I smoked a cigarette — I did everything I could to distract myself. And still, my mind was like ‘Go get that wine.’ It was really humiliating.”

About a week later, she headed to a feminist conference to give a speech but “had a little too much wine” before her talk.

“I talked too long and I was so embarrassed that I had kind of droned on in front of these women that I respected,” Grassle says, noting that she visited with an old friend afterward who had recently been to Alcoholics Anonymous.

“She confronted me — she knew that I had a drinking problem,” she says. “And I was just dumbfounded. I couldn’t see it.”

When she got home from the trip, Grassle tried not to drink at all, but wasn’t able to do it.

“I once again got drunk, had an argument with a dear, dear friend. I cried my eyes out. And the next morning I had just had it and I just said, ‘That is it. I must never drink ever again,’ ” she says. “And that’s what happened. I never did. I got some help, and I don’t think I could have done it without help.”

Just a few months after she went into recovery, Grassle’s father died of alcoholism, making her double down on her sobriety.

“I didn’t need anybody to tell me this is a killer disease,” she says.

As for her relationship with Landon, who died in July 1991 from pancreatic cancer, Grassle says they started off with a “wonderful rapport” on Little House, which aired from 1974 through 1983 on NBC.

“When I came on the pilot, he was extremely kind and sensitive and a good director and really gave me a chance to find my legs because [TV] was a new medium for me,” she says. “So I have to say it started out really, really great. It didn’t stay great.”

Going into the show’s second season, Grassle tried to negotiate a pay raise with Landon and the network but, she says, the Bonanza star did his best to get her to stand down.

“Mike began to have private conversations with me to get me to give in,” she says.

“He would say things like, ‘The network has done some testing and Ma is not the favorite character so they don’t want to give you more money’ or he’d say ‘You know, it’s a jungle out there’ or ‘Well, Karen there has to be some parity between you and the girls,'” she says, referencing the young actresses who played their onscreen daughters.

In the aftermath of the negotiations, in which Grassle was victorious, she says her character was featured in fewer scenes and Landon became “moody” around her.

The “worst of it,” she says, was his crude language during their one-on-one scenes filmed in the bedroom.

“I loved playing those scenes where we would talk over whatever the town crisis was and kind of flirt with each other, they were really sweet scenes, but he began to tell filthy jokes while we were sitting there in that bed, and I had nowhere to go,” she says. “I was trapped in that little bed in that little room, with men standing all around and there was light just on us. It was so humiliating.”

Grassle and Landon were able to reconnect in the years after the show ended and prior to his death. “Mike and I ended on a positive note and I was so, so glad for that,” she says.

Bright Lights, Prairie Dust: Reflections on Life, Loss, and Love from Little House’s Ma hits shelves Nov. 16.