If I Had Legs I’d Kick You is an anxiety attack, and filmmaker Mary Bronstein designed it that way

If I Had Legs I’d Kick You opens on a very tight close-up of Rose Byrne’s face. It immediately discombobulates the viewer.

We’re so used to being coddled, and then slowly lowered into a warm bath. If I Had Legs I’d Kick You is more like being abruptly being pushed into a cold plunge, clothes still on, and then no one gives you the ladder to get out.

The film is stressful because it’s meant to be, a visceral portrayal of a woman on edge, one teeny weeny nudge away from a full nervous breakdown. Byrne plays that woman, Linda, and she is deservedly firmly in the Oscar conversation for the performance of her career, so far.

That opening close-up is deliberate, of course it is. “This film is so subjectively in this character’s point of view, relentlessly,” writer and director Mary Bronstein told The Nightly. “She doesn’t get a break, so we don’t get a break from the character.

“We don’t see anything that she doesn’t see. We don’t hear anything she doesn’t hear. We’re not in a room where she’s not.

“This is a fully immersive, subjective experience. I felt from minute one when I was writing, the film must open as close as we can be on this woman’s face, and it’s going to teach the audience, this is what this film is, get used to this face because this face is the movie.”

Linda has a young child who is dangerously ill, and requires all her attention. You never see the kid, only the glimpse of a body part here, a silhouette there, but you hear her, and the whiny pitch of her voice is designed to grate even a Play School presenter.

She’s also a fulltime working therapist, her husband (Christian Slater) is away for work, and her own therapist (Conan O’Brien) isn’t what you call the sympathetic type.

When the ceiling in their apartment caves in and water floods the place from above, Linda and her child have to move to a nearby motel, where the young receptionist refuse to sell her a bottle of wine at 1.58am because there’s no alcohol service after 2am. The knocks just keep coming.

The chaotic soup that is Linda’s life is specific to her, but the spiral of anxiety is relatable to all. You don’t need to be a parent of a sick child, or even a parent, to understand that feeling of being overwhelmed by a really bad day.

“It’s about the person who is having stresses piled on top of each other, so that they all become kind of equal, and the overwhelming stress and anxiety of having a sick child becomes equal to not being able to get a parking spot,” Bronstein explained.

“Of course, those are not equal but when you feel like the universe is conspiring against you, it does feel equal. That when anxiety becomes like a monster that’s being fed, and that’s central to the film.

“My hope is that, and it’s my philosophy about art in general, is that the more specific you get, the more people can relate.”

If I Had Legs I’d Kick You screened at the Melbourne International Film Festival and Bronstein made the trip down under. At the festival’s after party at State Library Victoria, moviegoers kept approaching her.

“I was walking through and people were tapping me on the shoulder and everybody wanted to share a personal reaction,” she recalled. “One woman was crying and saying, ‘I was very sick as a child and now I understand what my mother (went through)’.

“They saw themselves in (the film) and they wanted to talk about it, and that’s what film is for.”

The feeling at the heart of If I Had Legs I’d Kick You, but the details are drawn in part from Bronstein’s life. Her daughter is now 15 years old and “happy and healthy and everything is good”, but when the child was seven, she had a serious illness.

Bronstein and her daughter had to move from New York City to San Diego and lived out of a motel for eight months. This project is personal to her, but in Bronstein’s mind, every piece should be.

Her previous film, Yeast, was released in 2008, so it’s been a long break in between. She wrote a lot of scripts during those years, but If I Had Legs I’d Kick You was the one she had to do.

“None of them were ones where if I didn’t make the movie, I would feel like a part of me would die. I needed to make this movie,” she said. “I landed on something that I really had to say, that if I wasn’t going to be able to say it, I didn’t know how I was going to move on.

“There’s an urgency and immediacy in that.

“I think that movies should only be made if the artist has something to say, not a movie for a movie’s sake.”

If I Had Legs I’d Kick You is in cinemas on November 13