Lily James had panic attacks after filming Rebecca

Lily James suffered from debilitating panic attacks after she played a troubled character in her new movie Rebecca.

The 30-year-old actress portrays Mrs. de Winter in the upcoming Netflix adaptation of Daphne du Maurier's classic Gothic novel, and she has opened up about how the character's "difficult headspace" affected her mental health.

"I found it really hard to let go of the character. She's really bullied and gaslighted, she lives in a difficult headspace," Lily said during a BAFTA masterclass at the 2019 International Film Festival & Awards in Macao. "I kept having panic attacks after it finished, I couldn't shake it off."

Lily also revealed that the film, directed by Ben Wheatley, will be "very different" from Alfred Hitchcock's Oscar-winning adaptation, which starred Laurence Olivier and Joan Fontaine and was released in 1940.

The story follows Mrs de. Winter as she begins married life with her husband Maxim, played by Armie Hammer, at his sprawling coastal family estate. However, oppressive housekeeper Mrs. Danvers, portrayed by Kristin Scott Thomas, constantly berates the young woman, and she is forced to live in the shadow of Maxim's dead first wife, Rebecca.

During the talk, Lily recalled her fond memories of working on TV series Downton Abbey and credited her former castmates - such as Maggie Smith and Hugh Bonneville - for helping her build her confidence.

"I learned to do screen acting in the most high-pressured environment - I felt like I couldn't make a mistake. But on the other hand, it was the best opportunity I could ever have been given, it's such an ensemble piece, so I was learning from the best straight away," Lily explained. "I'll be forever grateful for the job, we're still a family."