The famously awkward Twilight star's insecurities began as a child, when she was tormented at school because she was a real tomboy who suddenly didn't fit in with her male pals.

In an interview with Marie Claire, she says, "All of a sudden, it wasn't cool to be one of the boys anymore. (Suddenly it was), 'Kristen's not a girl. What is she?' And I just died. It was a totally cliched, very real insecure breakdown moment, when I was like, 'I f**king hate myself'.

"So many people say, 'Oh, it must have been so easy for you'. You think because I'm an actor that I didn't have a normal progression of self-hatred? When I was younger, I really wanted to be with the adults, to be addressed as a grown-up. I was the most open, forthcoming, confident little kid. I'm still trying to get back to that."

Stewart explains her issues continued and she really struggled under the microscope of fame.

She continues, "Between ages 15 and 20, it was really intense. I was constantly anxious. I was kind of a control freak. If I didn't know how something was going to turn out, I would make myself ill, or just be locked up or inhibited in a way that was really debilitating."

However, the 25 year old insists maturity has helped her deal with her emotions and it has even ignited a fierceness in her.

She adds, "At one point, you just let go and give yourself to your life. I have finally managed that and I get so much more out of life. I've lived hard for such a young person, and I've done that to myself - but I've come out the other end not hardened but strong. I have an ability to persevere that I didn't have before. It's like when you fall on your face so hard. And the next time, you're like, 'Yeah, so? I've fallen on my face before'."

She adds, "I used to be embarrassed about how I cry all the time. Now I think it's a gift to feel things. I needed to be slapped down a few times to learn that lesson. But I wouldn't trade it, to be honest. 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."

In the telling interview, Stewart also addressed public criticisms she has faced following her public romance and break-up with Robert Pattinson, adding, "I lit my universe on fire and I watched it burn. Speaking very candidly, it was a really traumatic period in my early twenties that kick-started something in me that was a bit more... feral.

"The public kind of burned me at the stake. But that's OK, I can take it. I'm not dead."