Reese Witherspoon is so badly plagued by insecurities that she almost walked away from her Academy Award-winning role in Walk The Line!

The 30-year-old, who took home Best Actress honors for the Johnny Cash biopic, says she was convinced she wasn’t sexy enough to make it in Hollywood. And she revealed that her paranoid thoughts almost made her quit Walk The Line in the middle of filming.

Said Reese: “I was so nervous, I threw up all day and had to have a sick bucket nearby. I thought I was going to be a failure.”

Surprisingly, Reese’s growing success has only highlighted her lack of self-esteem.

She said: “People want to move you into a place where you can be… this very likable woman. And it’s very hard for me. I just don’t see myself as the girl everybody likes. I never have been, and I don’t know how to be that person.”

In an interview with a freelance writer, the mom of two — who starred in Walk The Line with Joaquin Phoenix — also confessed that she was afraid she didn’t have the looks to be a success in Hollywood.

Admitted Reese: “I was constantly told, ‘No, not right. Not tall enough, not pretty enough, not sexy enough.’ Being sexy is not me, and I used to beat myself up about it.”

But now that she’s got an Oscar, Reese — who is married to hunk Ryan Phillipe — is learning to keep her demons at bay.

She said: “After years of giving myself a hard time, I now know I am so blessed.”