The singer felt he had a "split personality" because his person on-stage and out of the spotlight was so different, reported Femalefirst.
"It was straight off the back of the 'X Factor' tours. I was drinking too much, I'd always want a drink - vodka and orange - before I performed. You have this split personality.
"You save all the smiles and the happiness for the performance and then it was like you just switched off. I was moody all the time. I was like a zombie but underneath it all, I was just worrying about what was going to happen to me and I was actually depressed," he added.