'Otherside' superstar Macklemore has revealed that his past troubles with alcohol and drugs ran very deep. 

In a new chat with mtvU's "Half of Us" campaign, he explained that he first had a drink when he had just entered his teens and really overdid it: "[When] I actually drank for the first time, I was by myself. This is an indicator of who I was, from the jump. After school, by myself [at] 13 years old, maybe 14."

He continued, explaining that he really went for it: "12 shots in, [my] first time ever drinking alcohol. That's not people like, 'yo keep going.' That's me, by myself, solo in the kitchen, like I can't stop. I can't this turn this off. This feels good, I wanna keep going."

The hitmaker then added that his ambition to become a professional rapper was the one thing that 'pulled him back' and gave him the courage to back away from it:

"The thing that pulled me back was knowing that I wanted to be a musician, and that if I wanted to do this I had to get sober. So I'd go a month and be sober, make a bunch of music and then fall back off and vanish for a couple months and go back and forth like that. That's how I made music for the majority of my teen years and twenties."

Referring to his use of OxyContin, he added: "It's synthetic heroin, that's the definition of it. [I saw] the grip that it had, just doing it for five or six days, sweating through my sheets and coming off of it shaking."