(Cover) - EN Showbiz - Selena Gomez says it only takes one negative comment to make her feel bad about herself.

The gorgeous Disney star debuted her song Who Says during American radio show On Air With Ryan Seacrest yesterday. She explained the origins of the song, revealing it stems from real life experiences.

The star is currently dating Justin Bieber, and has been the victim of internet hate campaigns from a small number of his over-zealous fans. Some of his supporters are annoyed Justin has a girlfriend, and have slammed Selena on sites like Twitter. The 18-year-old tries not to think about the situation too much, but admits it gets to her at times.

"I feel like my fans need this song, especially with Twitter and Facebook it's really negative for me... within that world is such easy access to people's feelings, she explained. You can get a thousand wonderful comments but just one will throw you off and that's how it is with me."

The 18-year-old actress was rumoured to be dating Justin, 17, for months, but the couple only recently confirmed their relationship, making their first public appearance at the 2011 Vanity Fair Oscar Party last month.

Who Says features lyrics including: "You made me insecure/ Told me I wasn't good enough/ But who are you to judge/ When you're a diamond in the rough."

The brunette beauty believes the words are powerful and will mean a lot to her loyal fans.

"I think this song is such a great message for my fans, and it really touched me when I heard it, and I thought it would be perfect for them," she said. (C) Cover Media