Lady Gaga's poignant performance during Sunday's Academy Awards came as a surprise to many — including members of her own family who didn't know that she, too, was a survivor of sexual abuse. 
 
 The "Applause" singer took the stage during the ceremony to perform her Oscar-nominated song "Til It Happens To You" from the college sexual assault film "The Hunting Ground." Sitting at a white piano, Gaga belted out the tune she co-wrote with Diane Warren surrounded by several rape survivors who scrawled messages of transcendence on their bare arms. The segment was one of the most stirring moments of the evening. 
 
 OSCARS 2016: Full coverage | List of winners | Red carpet fashion 
 
 However, some members of the pop star's family — namely her grandmother and her aunt — didn't know that she endured abuse until they saw her perform. 
 
 "My grandmother and my Aunt Sheri both called me the day after the Oscars because I never told them I was a survivor. I was too ashamed. Too afraid. And it took me a long time to even admit it to myself because I'm Catholic and I knew it was evil but I thought it was my fault. I thought it was my fault for ten years," the 29-year-old wrote in a lengthy Instagram post Tuesday. 
 
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 "The morning after the Oscars when I talked to my grandmother Ronnie, with tears in her eyes I could hear them welling through the phone she said to me 'My darling granddaughter, I've never been more proud of you than I am today.' Something I have kept a secret for so long that I was more ashamed of than anything-- became the thing the women in my life were the most proud of. And not just any women, the ones I look up to the most. #BeBrave #speakup #tilithappenstoyou" 
 
 It comes as a bit of a surprise that her family members were in the dark about her past, given that the singer first opened about her abuse in December 2014. The Grammy-winner, whose real name is Stefani Germanotta, spoke out about her rape during a 2014 Howard Stern interview while discussing her song "Swine." She revealed that she had been assaulted by a man who was 20 years older than she was, and she kept the incident to herself for a long time. 
 
 "The song is about rape," she told Stern. "The song is about demoralization. The song is about rage and fury and passion, and I had a lot of pain that I wanted to release. ... I went through some horrific things, and I'm able to laugh now because I've gone through a lot of mental and physical therapy and emotional therapy to heal over the years. My music's been wonderful for me. But, you know, I was a shell of my former self at one point." 
 
 The singer lost the Oscar to Sam Smith's James Bond track "Writing's on the Wall" but still emerged a victor on Sunday night with the highly praised performance. 
 
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 Following the ceremony, Gaga revealed the struggle she went through to rehearse the song and thanked her stage companions for joining her and showing their bravery. 
 
 "Thank you for standing next to me on stage. Thank you for all the things you said, for listening to my story and sharing yours. I will never forget it. 50 survivors, so brave, relentless determination," she wrote. 
 
 51 ¿¿¿¿¿¿¿¿surviving and thriving A photo posted by Lady Gaga (@ladygaga) on Feb 29, 2016 at 4:22pm PST 
 
 The "American Horror Story: Hotel" star also said that she felt "a weight lifted" after performing the song and "like I didn't have to hide anymore," crediting the survivors for putting a smile back on her face. 
 
 After my performance last night I felt a weight lifted. Like I didn't have to hide anymore. looks like my outfit and this photo felt what I was feeling @brandonmaxwell @markseliger A photo posted by Lady Gaga (@ladygaga) on Feb 29, 2016 at 2:18pm PST 
 
 Thank you to the survivors for putting that smile back on my face. Your strength set me free because I knew I wasn't alone. A photo posted by Lady Gaga (@ladygaga) on Feb 29, 2016 at 3:37pm PST 
 
 In another photo, which also bore an emotional message, she's seen kissing her fiance, "Chicago Fire's" Taylor Kinney. 
 
 "I never thought anyone would ever love me because I felt like my body was ruined by my abuser. But he loves the survivor in me. He's stood by me all night proud and unashamedly. THATS a real man," she wrote. 
 
 I never thought anyone would ever love me because I felt like my body was ruined by my abuser. But he loves the survivor in me. He's stood by me all night proud and unashamedly. THATS a real man. ¿¿ A photo posted by Lady Gaga (@ladygaga) on Feb 28, 2016 at 7:24pm PST 
 
 Follow me on Twitter @NardineSaad. 
 
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 MORE: 
 
 The moments that made Oscars night a milestone for sexual abuse survivors 
 
 Lady Gaga and Diane Warren find healing power in 'Til It Happens to You' 
 
 How Lady Gaga won the Oscars without taking home a trophy
– Lady Gaga's performance of her Oscar-nominated song about sexual assault during the Academy Awards on Sunday was a powerful moment for a lot of people. The Los Angeles Times reports two of those people were the singer's own aunt and grandmother, who weren't aware she was a survivor of sexual abuse herself. "My grandmother and my Aunt Sheri both called me the day after the Oscars because I never told them I was a survivor," Gaga posted to Instagram on Tuesday. "I was too ashamed. Too afraid." She first opened up about her abuse at the hands of an older man when she was 19 during an interview with Howard Stern in 2014, according to CNN. Gaga said she blamed herself for her own sexual abuse for a decade, but her grandmother called her after Sunday's performance to tell her she'd never been more proud of her. "Something I have kept a secret for so long that I was more ashamed of than anything—became the thing the women in my life were the most proud of. And not just any women, the ones I look up to the most," she said on Instagram. The singer performed Til It Happens to You—written for The Hunting Ground, a documentary about campus sexual assault—while surrounded by rape survivors and following an introduction by Joe Biden.