Inside Lady Gaga's Oscar Rehearsals: Meeting with Sexual Assault Survivors Who Joined Her Onstage 'Was Healing and Life-Changing'

Lady Gaga may not have taken home the Best Original Song Oscar, but her emotional performance will likely go down as a momentous event in Oscar history.

At the end of her song “Til It Happens to You” – a poignant ballad inspired by The Hunting Ground, a documentary highlighting the campus rape epidemic – Gaga, 29, was joined onstage by 50 sexual assault survivors. The cathartic performance left many in the audience, from Rachel McAdams to Kate Winslet, misty-eyed on Sunday night.

“It was really a historic movement for this issue in our country, one that will be remembered and talked about for a very long time. Never before has this issue had this kind of attention, respect and prominence in a pop-culture context,” Amy Ziering, a producer on The Hunting Ground, tells PEOPLE, especially considering the filmmakers had “no idea” it would ever earn Oscar attention.

Leading up to the 88th Academy Awards, Gaga, who herself was raped when she was 19, spent hours in rehearsals connecting with the survivors who would go on to share the stage with her.

“She spent a great deal of time with the survivors throughout the rehearsal process, and they formed a unique and meaningful bond,” Ziering – who describes Gaga as “the most gracious, humble, down-to-earth, wise and deeply kind and compassionate person” – says. “Many of them told me that speaking with her and hearing her share her story and what she’d learned was healing and life-changing.”

Indeed, the pop star took to Instagram Tuesday morning to relive her emotionally exhausting rehearsals experience.

“The first day of rehearsal with all the survivors I could barely get myself together. My body was wrecked with inflammation and pain, crying and shaking the whole walk to the stage. The whole night before I did not sleep. The fear of knowing I would finally face that I belonged in that group,” she captioned a shot with survivors.

She continued: “I told them I was so sorry I couldn’t be Lady Gaga for them, that I couldn’t even get dressed. I could barely get through the song, couldn’t hit any of the high notes. Hair wet, sloppy tee shirt jeans uggs, tissues. They all hugged me and told me that it was okay because it was more real this way, that they understood that they were in pain too.

“They told me they were there for me to support me because they believed this message needed to be heard. Without them I never could have felt strong. They accepted me for me, at my lowest and that was good enough for them, so somehow through the magic of their courage they made it good enough for me too.”

The survivors’ liberating experience lasted long after the Oscars ended, as they met with Vice President Joe Biden, who earlier had introduced Gaga’s performance after also advocating for rape survivors and calling for reform.

“The vice president graciously stayed for well over an hour after the show had finished and spoke in-depth with each of the survivors who wished to meet him. Gaga was elated and grateful,” Ziering says.

“It was incredible to see: One survivor mentioned that her father had been a source of support to her during her ordeal, and the VP asked her to call her father then and there on her cell so he could speak with him,” Ziering adds.

Prompting conversations about sexual assault was Gaga’s intent going into the show. The Grammy and Golden Globe winner co-wrote the track with hitmaker Diane Warren, who was molested at age 12.

“I am myself a survivor. Diane Warren is herself a survivor of sexual violence, and we’re here tonight and very grateful to the Academy for giving us this world stage to reward survivors for being brave and coming forward,” the singer said on the red carpet before the show.