The "What About Love" was rushed to the emergency room the very same day his headlining tour was scheduled to kick off.
Originally, he thought he had the flu but was eventually diagnosed with a blood clot in his throat.
"It made my throat hurt so bad, for three days straight I wasn't even eating solid food," he told People.
Luckily, he's doing much better now but says he realized he needs to slow down. "The doctor said whenever I do a lot of traveling I don't get much rest," the 17-year-old explains. "I'm waking up at 3 a.m., then going all day, then not going to sleep until 12. He said I need a lot more rest, and I just need a break."
The singer postponed his tour to February 2014 instead and will take the stage for the first time since his hospitalization on Dec. 2 at KISS-FM's Jingle Ball in Dallas.