LOS ANGELES:-Sam Smith's anxiety almost ruined his performance at the Grammys. Despite his worldwide success, the 25-year-old singer admitted his nerves still get the better of him when he's performing his ''personal'' hits and whilst he thought he would have ''more control'' over his anxiety when on tour, but it consumes him to the point of suffering panic attacks. He said: ''The other night - the opening night, at Sheffield - I was shaking, it's a vulnerable feeling. I thought I would be OK by now but my music is so personal, I feel like an open wound.''