The Backstreet Boys star admits he only stopped taking illegal substances when he was diagnosed with cardiomyopathy, a potentially fatal heart condition.
He said: “I realised I didn’t want to die. I didn't want to be that person people read about and think, 'That's sad that he couldn't stop it and killed himself.’ ”
The 29-year-old singer says it took him 10 years to accept he had an alcohol and drug problem. Even being charged with driving under the influence (DUI), getting caught up in a bar brawl and his ballooning weight – which crept up to 224lbs – were not enough to make him stop.
He eventually sought help after experiencing chest pains and fatigue last spring.
Nick underwent tests with a Florida doctor, but embarked on a huge cocaine binge the evening before the results were due.
He said: “I went out and just went nuts. I drank so much and I did a bunch of blow. I felt like I was trying to kill myself – because I didn't want to get the results.”
Nick eventually listened to the doctors and has quit drugs and lost 57lbs.
He now claims he is in the best shape he has ever been, adding life is “awesome”.