British pop sensation Lily Allen has cancelled most of her spring U.S. tour saying she has been "getting really drunk" and is "tired."

Allen posted the news on her MySpace page, and said she thinks her live shows have suffered. She said she increased her drinking recently because she was "so nervous about doing bad shows."

On her April 16 post, Allen first jokes that: "I thought that being a popstar meant going out getting trashed with famous people and sleeping in all day. The fact that this is not true has come as a huge disappointment to me."

Then she gets serious:

"I am not falling apart at the seams, I am not suffering with exhaustion, I am not pregnant, and I am not going to rehab. I will be here in America, promoting the album and also starting to write the second album, which I am beyond excited about," Allen said on her web page.

About 10 shows are affected. A spokesman for Allen said they would be re-scheduled for the fall and reiterated the 21-year-old singer would be playing at the Coachella Valley Music and Arts Festival in California (April 29) and Bonnaroo Music & Arts Festival in Tennessee (June 15).  She will also honour her concert dates in Seattle, Los Angeles and Charleston, S.C.

Allen's tour was in support of her debut album Alright, Still, which is riding on the popularity of the single Smile.

The move seems contrary to the wild child image Allen has cultivated. Some of her other posts on the MySpace page indicate the singer has been questioning her U.S. tour.

"Life is weird at the moment. Is it really important to break America?" said one recent post.

And another: "As much as I love driving across America and doing the same thing every night, I'm bored slightly."