Penelope Cruz would be "completely lost" without her work.
The 'Pain and Glory' star - who has children Leo, eight, and Luna, six, with husband Javier Bardem - is "addicted" to acting and can't bear the idea of not being cast again.
She said:" I started when I was 17 and I still remember when I finished my first shoot.
"I thought, 'If it's the last one, I won't be able to take this.'
"If it all stopped, I would feel completely lost and wouldn't know what to do with my life.
"I realised that performing had become an addiction.
"It was my life and it's been my life since I was a kid."
The 45-year-old actress feels "very lucky" to have always had a steady stream of acting jobs, particularly because she has friends who haven't been so fortunate.
She told Britain's HELLO! Magazine: "I've been very lucky, you know.
"I have not been out of work.
"But I cannot say, 'Oh I don't even know how that must feel.' No, because I have a lot of friends who are in that situation, unfortunately, and they are very talented but don't have a job.
"So I'm very, very grateful for what I have."
However, Penelope no longer accepts as many roles as she used to because she wants to put her family first.
She explained: "I've always been addicted to my family and it's even more the case since I've become a mother myself, and this is what has saved me from many problems and has helped me connect to my life."