Dame Helen Mirren has admitted she sees the "abyss" when she treads the boards and has to combat stage fright.
The Oscar-winning actress, 69, won her first Olivier Award for her performance in The Audience in 2013 and was dubbed the Queen of Broadway after the play transferred to the US.
But the star told Radio Times magazine she still suffers from nerves and that she intends to retire.
"Theatre is always nerve-racking. I'm afraid of losing my voice, having enough energy, and not getting sick," Dame Helen said.
"Every actor has stage fright, but there are levels, from serious psychotic breakdown, where you lock yourself in your dressing room and refuse to come out. It's happened to a few actors.
"Not me, but when I'm on stage I see the abyss and have to overcome it by telling myself it's only a play," she said.
"I don't know why we should feel like this. If something goes wrong audiences are wonderfully accommodating."
The actress told the magazine she intends to stop working.
"Yes, it would be quite nice. I don't think 'dying on the job' is such a wonderful thing.
"But I'm driven by competitiveness, always thinking I can do better, and the sheer pleasure of earning a living - a fabulous miracle I've never quite got over," she said.
She denied "insanely and outrageously wrong" reports that she is one of the highest paid actresses in Hollywood, saying: " What else can you do but laugh, so long as the taxman doesn't take it seriously."
Dame Helen said that actresses still find it more difficult than male counterparts to find work in the industry.
"I've been lucky, but if you look at any drama it's still five-to-one men to women," she said.
"There are a few women in main roles and although it's changing it's still difficult for most to earn a living.
"Many I grew up with are immensely talented yet can't. It's much easier for men."
In her new film, Woman In Gold, the actress plays Austrian Jewish aristocrat Maria Altmann, who fled Vienna during the Second World War and had a long battle to reclaim a Gustav Klimt portrait of her aunt which was looted by the Nazis.
"Anti-Semitism is still pertinent. People start down that particular road saying they're nationalistic or proud of their nation, rubbish like that, and set themselves on the first step to horrors," she said.
"It's happening again, not just in Europe. It seems to be an endless human story.
"I hope films can address ideas and thoughts that seep into the culture and push society forward.
"It's incredibly important to the way we form our thoughts and understanding of how life is and how to behave."
The film got mixed reviews when it debuted at the Berlin film festival.
"It was a mistake rushing it to Berlin before the editing was finished," she said .
"We paid the price, which I regret. It's an interesting story about a very powerful subject. I want it to do well because I didn't like to let Maria down."
Dame Helen said she attempts to avoid controversy now because people can get "into such trouble with the internet".
Asked about recent suggestions that sex education should include porn, the star, who felt traumatised when she saw a sex education film with graphic scenes of childbirth at the age of 14, said: "I don't know if that would be any more or less horrendous than mine, but they'll watch anyway. The accessibility is unbelievable."