Buckley, who is also a Mercury Music Prize-nominated singer, told presenter Lauren Laverne she did not regret her struggles.
“I didn’t know how to be alive the way I wanted to be, and it was difficult,” she said. “But I do not for a second regret it, and I think I’ve been able to transform it and recognise our vulnerabilities as humans in the world.
“You can’t walk through life not being affected, but you can transform that into something that allows you to be more human and alive in the way that you want to be.”
She said when she moved to London she “still wasn’t out of the woods”.
“There were moments where I was like, ‘if I don’t get better here, this music, this being part of theatre – I’m not going to be able to do this any more, and I probably won’t survive’,” she said.
“And that was the thing that turned it in my head. I was like, ‘I don’t want to sacrifice that, this is bigger than that’, and won.”
Buckley has already collected a Golden Globe and a Bafta, among other awards, for her performance in Hamnet – based on Maggie O’Farrell’s novel of the same name.
She told Laverne that the first time she performed on stage: “It was like drinking water, you know? I just think, the more I did it, the more I realised, this is essential to me.”