Jessica Brown Findlay, who is starring in Hulu's new drama "Harlots," is opening up about her eating disorder that she's suffered from since she was a teenager.

"I've had an eating disorder since I was 14," the 27-year-old "Downton Abbey" star told The Daily Telegraph. "And I think that we can feed certain ideas of what beauty is and what success is, and I just feel there has to come a time where those aren't the rules anymore, and then we can have a mature conversation about what that is about, and about depression."

WATCH: Lily Collins on Playing an Anorexic Following Her Own Eating Disorders: 'It's a Topic That's Taboo'

Findlay admitted that she used to be scared to talk about her disorder in public, but now hopes that it will help other people get the help they need.

"If you are lucky enough to speak and be heard, it might be something that could be useful to others," she said. "The more we have brave discussions like that going forward, the easier it is to talk about things, and the less alone we can feel. It's certainly made me feel less alone."

"I felt so alone for so long, and I just hid," she continued. "And then I started talking and held my head up, and instead of saying 'sorry' decided to tell myself that I matter."

NEWS: 'Downton Abbey' Star Dan Stevens Joins 'Beauty and the Beast'

She explained that when she started going to therapy, she realized it was good and healthy to talk about her issues.

"It's about learning to stand up and say, 'This is me, and that's OK,'" she said. "I'm not going to be a better actor if I'm a dress size smaller. It's nothing to do with my brain."

WATCH: Mel C Opens Up About Developing an Eating Disorder While With the Spice Girls