Inside Charlie Puth's Scary Illness on Tour: 'I Had to Get Shots in My Butt Just to Get on Stage'

Just before taking the stage at Z100's Jingle Ball in New York City on Friday, Charlie Puth tells PEOPLE he is ready for a break. "Absolutely nothing," he said, when asked if he had any holiday plans. "I've been touring nonstop ... I was sick and I had to have like tetanus shots in my butt just to get on stage at one point, I was so sick." He clarified, adding, "Not tetanus shots -- steroids or something like that. It's crazy. I'm looking forward to just resting." The "We Don't Talk Anymore" sin...