Cory Monteith may play a lovable jock on 'Glee,' but the 29-year-old actor says he has few similarities to his character on the hit Fox series. In fact, the high-school dropout says he battled with drug addiction in his teens, reports People.

"I'm not Finn Hudson," Monteith says in an interview with Parade magazine, adding, "I'm lucky on so many counts -- I'm lucky to be alive."

At age 13, the Canadian actor was skipping school, getting drunk and smoking marijuana, and "was out of control" by age 16 when Monteith's drug use advanced beyond pot. "Anything and everything, as much as possible," he says. "I had a serious problem."

At 19, Monteith headed to rehab after an intervention by his mother and friends, but his sobriety didn't last long. "I did the stint but then went back to doing exactly what I left off doing," he admits.

The 'Glee' actor turned his life around after receiving an ultimatum from a family member from whom he stole "a significant amount of money." The relative said: get clean or face robbery charges. Monteith chose the former. "I was done fighting myself. I finally said, 'I'm gonna start looking at my life and figure out why I'm doing this.'"

This isn't the first time the multi-talented star has admitted to his bad boy past. In a 2010 interview with GQ, Monteith said he found himself "in some places that I'm very fortunate I came back from." However, he doesn't want his fans to follow in his footsteps.

In his Parade interview, which hits newsstands on Sunday, he adds, "I don't want kids to think it's okay to drop out of school and get high, and they'll be famous actors, too ... But for those people who might give up: Get real about what you want and go after it."

Watch Cory Monteith Talk About His Newfound Fame on 'Jimmy Kimmel Live'