Kelly Clarkson was forced to withdraw from the remainder of her U.S. tour due to voice strain. "So bummed that I have to cancel some of my tour dates. This kills me, but doctors are saying I need to rest my voice," Clarkson wrote in a series of tweets Saturday. "I was like, 'Oh, God, I'm not going to be a singer anymore!' Barring any more setbacks, Clarkson is scheduled to resume her trek in support of Piece By Piece October 1st at Kanata, Ontario's Canadian Tire Centre.