The 23-year-old star played the titular wizard in all eight movies of the blockbuster franchise.
He was worried at the end of his work on the film series that he wouldn't be good enough to tackle other roles and hates having time off as his concerns escalate, reported Radar online.
"With any kind of artistic thing it's a muscle, like any athlete, and the moment you're not doing it, you lose all confidence.
"That's why I'm terrible with down time. And actually what's been great about the last year and a half is that I have found a confidence. Before, basically, by the time we got to the end of 'Potter', I was going, 'I don't know if I can do this, I don't know if I'm good enough'," Radcliffe said.
The movie star has since starred in "The Woman in Black" and also landed a role in "A Young Doctor's Notebook" which is a TV adaption of Mikhail Bulgakov's novel 'A Country Doctor's Notebook'.
He said that he was overjoyed when he was approached as he is an obsessive fan of the Russian author.
"They had no idea, that I was this obsessive fan. I read it and immediately loved it, and read it again immediately afterwards, and then, for my 21st birthday I went to Russia to visit his apartment, as my present to myself," he added.
