Anna Clendening has suffered from an anxiety disorder for the past six years, often rendering her unable to leave the house, even causing her to doubt her desire to live. Then the 20-year-old from Chapel Hill, NC discovered a gift for music. Anxiety couldn't stop her from appearing on this week's episode of "America's Got Talent" to share that gift. In this segment, Clendening explains the challenges she's faced and mustered the courage to perform Leonard Cohen's "Hallelujah" before the packed room and the world. Her jaw-dropping performance leaves the audience cheering on their feet and earns a hug from judge Howie Mandel, who also contends with anxiety