Juno star Elliot Page recalled a time he "lost it" after he had to wear a dress for the red carpet.
The Hollywood actor opened up about the "profound discomfort" with his body before coming out as transgender in an interview with Oprah Winfrey.
Page, who came out as transgender in December, admitted dressing in feminine clothes made him feel "ill".
"It was total hell, absolutely," he told Winfrey in an interview released on Friday.
"I think before puberty if you're a tomboy, it can be somewhat accepted or dismissed. But then when I got to puberty and at that age, that wasn't ok anymore. And that's when a lot of teasing began and mostly just the beginning of just very profound discomfort in my body and disconnection from my body.
"And I was acting too, so going to set every day and changing into clothes that really made me feel ill."
In the Paris premiere of Inception in 2010, Page admitted he just "lost it" after his manager presented him with three dresses.
"We got back to the room and she was like, 'I have a surprise', and like, I already had to wear the dress, had one picked out.
"And I went in and there were three dresses laid out, like new dresses to maybe see, and I just lost it. I got so - it was a cinematic moment."
Page also described collapsing the night after the premiere in what was likely a panic attack.
"That night after the premiere and the after-party, I collapsed. And that was something that's happening frequently in my life, usually corresponding with a panic attack," he said.
"[There were times when] I felt like I was barely existing."
The Juno actor spoke out for the first time because he wanted to address a wave of laws in states across the US seeking to cut back gender-affirming care.
"Children will die," Page said. "And it really is that simple."
Page told Winfrey coming out as transgender in December and sharing it on his platform was "imperative" in light of the "horrible backlash" against trans youth.
"With this platform I have, the privilege that I have, and knowing the pain and the difficulties and the struggles I've faced in my life, let alone what so many other people are facing, it absolutely felt crucial and important for me to share that."