Kristen Stewart has revealed she was so stressed out by fame she used to vomit every day.

The 26-year-old was catapulted into the limelight in 2008 when she starred as Bella Swan in the teen vampire movie saga Twilight, alongside co-star, and former boyfriend, Robert Pattinson.

The actress told Elle magazine in an interview this month (Aug16) she struggled to deal with the overwhelming fame, and had panic attacks while vomiting on a daily basis.

"I went through so much stress. I had panic attacks, I used to puke every day and very casually, too," she explained. "I didn't have an eating disorder; it wasn't to do with that. I always had a stomach ache. And I was a control freak.

"I couldn't anticipate what was going to happen in a given situation, so I'd be like, 'Maybe I'm going to get sick' and then I'd be sick."

Kristen opened up about her mental health issues, and revealed she was trying to curb her obsessive compulsive disorder (OCD).

"As I am getting older I'm going into my OCD. If things are a mess, I feel like I have lost everything. So I procrastinate by tidying, which is so stupid.

"I say to myself, 'Just do what you need to do. If you want to write something, if you need to get a thought out, if you need to call someone about something creative, do it now! You don't need to organize your desk first,'" she added.

The Cafe Society star confessed, "I changed, that's the thing - at a certain time point I realized that the fear was death, but I had gone through so much that did not kill me... sorry, I know that sounds dramatic... I realize the anxiety just ran out. I didn't have the energy to do that anymore."

The actress garnered a huge following when she starred as the heroine in the film adaptations of Stephenie Meyer's teen vampire books, and her subsequent relationship with her co-star Robert Pattinson turned her life into a media frenzy.

The pair began dating in 2008, but later split when she was pictured in a passionate embrace with her Snow White and The Huntsman director Rupert Sanders in 2012. Kristen reconciled with her actor beau, but they later split for good in 2014.

Now, the actress is in a relationship with special effects producer Alicia Cargile, and she revealed to the magazine dating men is so much more stressful than dating women.

"When I was dating a guy I was hiding everything that I did because everything personal felt like it was immediately trivialised, so I didn't like it... But then it changed when I started dating a girl. It opened my life up and I'm so much happier.'"

Despite her mental health struggles, and anxiety issues, the actress is hopeful of a more positive, and stress-free, future.

"I obviously hope everything going on right now will work out, but I am confident that life is good and I'll be OK whatever happens," Kristen said."So in moments when that is cloudy and I feel saturated and unable to engage in how good life can be, however consuming those feelings are, they are so momentary... I'm think pretty good at being happy."

Kristen stars in Woody Allen's Cafe Society, alongside Jesse Eisenberg, which is released in September (16).