"I was living alone, and I think I was really freaked out. I drank a lot," the British actor, 26, revealed.
He explained that his alcohol dependence resulted from what he described as a fear of returning to reality after playing J K Rowling's popular boy wizard for more than a decade.
"I think it was more to do with going out in public and having a battle within me of thinking no, I can have a totally normal life. You get bored of waking up feeling like that," he said.