Reese Witherspoon was hypnotised to overcome her insecurities.
The 38-year-old actress - who is nominated in the Best Actress category for her portrayal of Cheryl Strayed in 'Wild' at this year's Oscars - admitted years of being told she was too fat or short for Hollywood roles had taken their toll on her self esteem, so she turned to hypnosis for a confidence boost before taking on the gritty role.
She said: "People may think I have this dream life, but for years I worried about my looks.
"I thought I was too short or not thin enough to be a Hollywood star. I was constantly being told, 'No, not right, not tall enough, not pretty enough, not sexy enough'. I wasn't allowed to audition for roles because they saw me as too cute and girlie.
"So I decided if I was to succeed I had to face facts. I could never be the sexiest, thinnest girl in Hollywood.
"[Hypnosis] was so helpful. I get panic attacks, especially right before I start a movie.
"Half the time on set I feel like I'm hanging on by the seat of my pants and I don't know what the heck I am doing."
The blonde beauty - who won the Best Actress Oscar in 2006 for her role in the Johnny Cash biopic 'Walk The Line' -also opened up about her decision to start her own film production company, Pacific Standard, in 2012, after realising there weren't enough lead roles for women being developed in Hollywood.
According to The Sun newspaper, she said: "Other than one studio, literally one, nobody was developing anything with a female lead.
"It just hit me like a ton of bricks and I was so mad.
"I had stories I wanted to tell and I'd become increasingly frustrated."