Kim Cattrall has opened up about the "debilitating" insomnia that caused her to pull out of a lead role on the London stage.In an interview in the new issue of Radio Times magazine, the Sex and the City star spoke candidly about the condition that forced her to give up the starring role in Penelope Skinner's play, Linda, at the Royal Court Theatre in November 2015."It was a gorilla sitting on my chest. I didn't understand the debilitating consequence of having no sleep. I was in a void," she told the magazine, according to The Guardian Less than a week before opening night, Cattrall announced that "with great sadness and at the advice of my doctors," she would not be continuing with the production. Her role was recast with Noma Dumezweni, who is now set to star in the Harry Potter play, Harry Potter and the Cursed Child: Parts I & II.“I didn’t want to let down the audience, the theatre, playwright, or the actors," Cattrall said. “Letting go of all that was the hardest part, but I realized the work that I really needed to do was more important than the play — it was work or my sanity.”Though her decision to drop out of the role prompted criticism on social media, she says she didn't listen to the "noise."“I have my own voice on social media, where I can say: ‘If you’re interested in what really happened, the whole story is more complex than being disease of the week’, than someone saying, ‘I have this battle,'” she told Radio Times.