Troian Bellisario has been in recovery from an eating disorder for a decade now, but that doesn't mean that the struggle is completely behind her.

The 31-year-old Pretty Little Liars star still faces setbacks when it comes to taking proper care of herself and her body, and to this day has to work hard to quiet the destructive voice in her head.

'There is a part of my brain that defies logic,' she wrote in a new essay for Lenny Letter. 'Even though I have lived in recovery for ten years now, it still finds loads of fun, insidious ways to thwart me to this day. It was a difficult journey finding my way back to health.'

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Her truth: Troian Bellisario has opened up to share more details about her eating disorder and how it still affects her today

Art imitates life: The 31-year-old wrote, directed, and stars in Feed, a new movie about a girl with an eating disorder

Troian has spoken candidly about her eating disorder in the past.

In a 2014 issue of Seventeen, she revealed that she used to withhold food from herself — or other privileges — 'based on how well I did that day in school'.

In her new Lenny Letter essay, she elaborated, admitting that there was a point when she would allow herself just 300 calories a day — and eventually, even that became 'too much'.

When she was restricting her food intake, though, it wasn't just about being skinny, though that was part of it. Mostly, it was about maintaining control.

She explained that since her illness began, she's had a little voice in her head that urges her to do things that she shouldn't.

It was that voice that told her she should subside on 300 calories a day when she was younger, and it's that same voice she still has to work to beat back.

'It's just not that easy,' she said. Sometimes I still find myself being pushed by an invisible taskmaster, working to the point of exhaustion, swimming with numb toes.

A complex tale: In the film, her twin brother (played by Tom Felton) dies and she limits her food intake to regain control of her life

Details: Troian admitted in a piece for Lena Dunham's Lenny Letter that she once restricted herself to 300 calories a day because of her illness

'The voice of my disease is with me every day. I am practiced at ignoring it, for the most part, but it's still there, finding new ways to undermine me.'

When she was filming the pilot for Pretty Little Liars back in December 2009, she had this voice to contend with. It was freezing, but the scene she and her castmates were shooting was set in the summer — so they were woefully under-dressed.

Fearing she would be seen as unprofessional or a diva, she didn't speak up about how cold she was, even when her toes started to grow numb.

'Wanting to be the most professional I could be, I sniffed back the snot that was threatening to ruin every take and forced my shoulders to stay where they were, even though I could see my breath on the air,' she wrote.

'I looked around: Lucy, Ashley, and Shay all seemed cold but fine; they looked professional, powerful.

'Was I not cut out for this? I pushed that thought out of my mind. Suck it up, Bellisario, do your job.'

And when she finally mentioned that she had lost feeling in her feet, she admitted to feeling incredibly guilty when one of the crew offered her help, fearing that people would judge her behavior.

Scoop: The actress also recalled shooting the Pretty Little Liars pilot and being so cold her toes went numb — yet being afraid to speak up for herself

Flashback: Troian (pictured in high school) has been in recovery for about ten years

'Everyone is going to think I'm a diva, that I can't hack it, that I'm a horrible actor, and they'll never want to work with me again,' she wrote.

Interestingly, Troian noted that she learned a lesson from the experience, asking why she 'needed a complete stranger's permission' in order to look after herself.

But, seven years later, the actress admits that this is still something she struggles with on a daily basis.

To illustrate her point, Troian described another incident that took place recently, in which she and a friend challenged themselves to swim three times around a freezing lake.

Troian had started to go numb during lap two — but instead of taking care of herself and getting out of the water, she pushed on, feeling like she had something to prove.

'As someone who struggles with a mental illness, my biggest challenge is that I don't always know which voice inside me is speaking,' she went on.

'My body voice, the one that says, Troian, I'm cold, get out of the lake, or my illness: You told everyone three times, so you can't disappoint them. You are not enough.'

She hopes that her new movie, Feed — which she wrote before even signing up for Pretty Little Liars — will help other young people with similar problems come out on the other side like she did.

'Through hard introspection, intense medical and mental care, a supportive family, friends, and a patient and loving partner, I survived, which is rare,' she said.