"We're not machines, and we are expected to turn it on and off," Witherpsoon admitted during The Hollywood Reporter's drama actress roundtable

Credit: Getty (3)

Oprah Winfrey, Reese Witherspoon and Nicole Kidman are veterans in TV and film, but even they struggle with turning off their characters when the cameras stop rolling.

Earlier this year, the trio of actresses starred in two acclaimed HBO drama series: Winfrey in The Immortal Life of Henrietta Lacks and Witherspoon and Kidman in Big Little Lies.

Sitting down for The Hollywood Reporter‘s annual drama actress roundtable — along with Chrissy Metz (This Is Us), Jessica Lange (Feud) and Elisabeth Moss (The Handmaid’s Tale) — the three veteran actresses opened up about the difficult aspects of current and past roles that they’ve played, and how embodying each of this season’s characters impacted them personally.

In 2013, Winfrey starred in Lee Daniels’ The Butler as Gloria Gaines. During the candid interview, Winfrey recalled internalizing the emotions of her character and feeling the need to “burst into tears” after she left set.

“I had a scene where my son had died and I had gotten myself to the point where I’m ready to just let it all go, and the director, Lee Daniels, said, ‘Nope, I don’t want her to do that. I don’t want her throwing herself all over the casket. I just want her to hold it, hold it, hold it, hold it …’ And so, I didn’t release it. I left that scene, got on a plane, went to interview somebody else and was holding it …” said Winfrey, 63.

“Holding all of that energy in the middle of an interview, I thought I was going to burst into tears in the middle of somebody talking about something that was not even related to me bursting into tears,” admitted the former Oprah Winfrey Show host. “And I felt a little cuckoo. I realized it’s because I didn’t go through the process of letting go.”

RELATED VIDEO: Why Oprah Felt ‘Intimidated’ To Star In ‘The Immortal Life Of Henrietta Lacks’

Similarly, Kidman felt both the physical and mental weight of her character’s — Celeste Wright — tribulations while filming an abuse scene in BLL.

“There was one point when [director Jean-Marc Vallee] wanted to go back and reshoot me being slammed into the wardrobe because it wasn’t hard enough. I’m like, ‘I’ve got bruises because of how hard it was, so I can’t believe that it didn’t read that way.’ But as we all know, on film sometimes what you’re feeling doesn’t read. I felt my way through the character,” said Kidman, 49, who largely did not utilize a body double and filmed the majority of the violent scenes herself.

While filming the final scene of the episode, Kidman remembered lying on the floor of the set in her underwear and not being able to move.

“I just lay on the floor. I couldn’t get up. I didn’t want to get up. And I remember Jean-Marc coming over and putting a towel over me in between the takes because I was just like …,” she said. “I just felt completely humiliated and devastated. And angry inside. I went home and I threw a rock through a glass door.”

After throwing the rock through the glass in her hotel room, Kidman called her BLL costar, Witherspoon, to whom she confessed.

“We were staying at a hotel and she called me and she says, ‘I’ve just done the craziest thing.’ She got home from work and she had one of these horrible scenes and she goes, ‘I couldn’t get into my hotel room so I threw a rock through the window,’ ” Witherspoon explained. “And she goes, ‘I don’t do stuff like that.’ ”

In reflection of that emotionally taxing day, Kidman said, “I was obviously holding all that rage and what had been done.”

RELATED VIDEO: Spoiler Alert! ‘Big Little Lies’ Director on Violent Season Finale, Plus Will There Be a Season Two?

Reese Witherspoon

Like Kidman, Witherspoon — she played Madeline Martha Mackenzie on the HBO drama — also had a breaking point during filming of BLL.

“We were shooting the finale and we were on our seventh day of night shoots, and I was losing my mind. And they kept saying, ‘OK, we’re going to do the scene where you have the breakdown and you tell Shailene [Woodley’s character] that you’ve cheated on your husband.’ And then they’d be like, ‘We ran out of time. We’re going to do it tomorrow,’ ” Witherspoon, 41, explained.

But after a week of preparing for the scene, which was continually being pushed back for filming, Witherspoon couldn’t take it anymore.

“I started to scream, and I’ve never screamed like this. Like, howling. And instead of having this feeling — like, ‘Oh, my God, what did I just do?’ — all the women came over and said, ‘Girl, I have so been there,’ ” Witherspoon said. “And Nicole goes, ‘Jean-Marc, she’s ready to shoot right now, right now. We need to get Jean-Marc.’ ”

Through starring in over 100-plus films throughout her three decades in Hollywood, Witherspoon can speak for a majority of leading actors about one of the most frustrating elements of their profession.

“We’re not machines, and we are expected to turn it on and off,” said Witherspoon, who added, “and sometimes it’s the most maddening aspect of what we do.”