The Crown star has given a candid interview in which she describes her long-running doubt about her talent, which she used as a “tool to survive”.
The 34-year-old spoke to the Guardian about her youthful determination to please her parents and those around her, and the struggles she faces as a parent herself.
She said of her anxiety: “The thing about it is, it’s not related to anything that would seem logical. It’s purely about that feeling in the pit of your stomach, and the feeling that you can’t.
“It was a tool to survive. To try to feel safe.”
Foy has worked alongside Ryan Gosling in forthcoming film First Man, about the Apollo 11 space mission.
She has achieved an international profile for her work, but says she still doubts herself in anxious moments.
The birth of her daughter also brought its own challenges.
Foy told the Guardian: “You become someone’s parent - and suddenly you’re supposed to be capable? Have all the answers? Know what to do every day?”
First Man is due for release on October 11.