Billie Eilish performed a cover of "Yesterday" by The Beatles for the2020 Oscars'"In Memoriam" segment.On Thursday, she revealed to Zane Lowe that she was sick during the ceremony."I was sick for all of the Oscars, I bombed that performance," she told Apple Music's New Music Daily host. "That s--- was trash."Visit Insider's homepage for more stories.As the saying goes, many of us are our own worst critics ' and that certainly seems true for Billie Eilish, who thinks that she "bombed" her performance at the Oscars on Sunday.The 18-year-old phenom revealed to Zane Lowe on Thursday that she was sick during the ceremony, where she performed a haunting cover of "Yesterday" by The Beatles for the show's "In Memoriam" segment."I was sick for all of the Oscars, I bombed that performance," she told Apple Music's New Music Daily host. "That s--- was trash."Eilish also said the experience was "so scary" because it was a different crowd than she was used to."It was also, like, the Oscars is not my people," she said. "I'm not used to that. At least the Grammys wasn't as scary because it was, like, artists, and it felt like my people.""I knew a lot of them already and I'd met them and they knew of me ' but, like, the Oscars, I'm like, 'These are movie stars.'"Watch Eilish perform with her brother and producer, Finneas O'Connell, at the Oscars below.Read more:The best 2020 Oscars memes included Billie Eilish reactions, Eminem confusion, and plenty of love for Bong Joon HoBillie Eilish answered AI-generated questions and said the biggest thing she's missing out on is working at Jamba Juice or Trader Joe'sWatch Billie Eilish's stunning performance of 'When the Party's Over' at the GrammysBillie Eilish thought she wouldn't finish her 2019 tour because of stress: 'I was worried I was going to have a breakdown and shave my head'Join the conversation about this storyNOW WATCH: Apple forever changed the biggest tech event of the year by not showing up Click here to read full news..