Kristen Stewart admits her early 20s were a 'traumatic period' which left her 'constantly anxious'

Kristen Stewart has admitted that she felt 'constantly anxious' during her early 20s, which was a 'traumatic period' in her life.

The A-lister, who started acting as a child and rose to worldwide fame in her late teens, claims that she began to embrace all the labels thrown at her as she found herself under the media spotlight.

In a new interview with Marie Claire, she said: "I lit my universe on fire and I watched it burn."

She added: "Speaking very candidly it was a really traumatic period in my early 20s that kick-started something in me that was a bit more feral."

The star, now 25, admitted that she found coping with fame as a younger star a 'debilitating' experience.

She said: "Between ages 15 and 20, it was really intense. I was constantly anxious. I was kind of a control freak.

She added: "I'm really proud that I am able to move forward and not fall into every mental crater. That's a new thing for me. Age has made me smarter and calmer. And it is f**king awesome."

Stewart is currently filming her role in Ang Lee's new military drama Billy Lynn's Long Halftime Walk, before she starts on Woody Allen's new project, co-starring Blake Lively and Bruce Willis.

The full interview with Kristen Stewart is in the August issue of US Marie Claire, on newsstands July 21.