Shailene Woodley was struggling with a ''deeply personal, very scary physical situation'' at the beginning of her career.

The 28-year-old actress revealed that when she was starring in the 'Divergent' series of films at the beginning of her career, she was secretly battling a terrifying illness which almost derailed her career.

She told The New York Times: ''I haven't spoken much about this yet publicly, and I will one day, but I was very, very sick in my early 20s. While I was doing the 'Divergent' movies and working hard, I also was struggling with a deeply personal, very scary physical situation.

''Because of that, I said no to a lot of opportunities because I needed to get better, and those jobs ended up going to peers of mine who I love.

''There was a mix of people saying, 'You shouldn't have let that go' or 'You shouldn't have been sick' That was combined with my own internal process of, 'Am I going to survive what I'm going through right now and ever be healthy, or even have the opportunity to work on projects I'm passionate about again because of the situation I'm in?' I was in a place where I had no choice but to just surrender and let go of my career, and it brought out this negative voice in my mind that kept spinning for years and years afterward.''

The 'Big Little Lies' actress says she has now recovered and has been working on her mental health over the past few years.

She said: ''Now I'm on the other side of it, thank God. A lot of the last few years has been about focusing on mental health for me, and it's a slow process. But because of that work, I feel very grounded and rooted in who I am and very clear about everything in my life, whether it's my career or my relationships or my own internal worth. I feel very grateful to have walked that line of fire, because now I know what I don't want to ever go back to.''