The 'Fifty Shades of Grey' film adaptation, which has completed production, went through a tumultuous time before filming even began, British actor Charlie Hunnam dropped out of playing Christian Grey just weeks before shooting was scheduled to start.

Charlie Hunnam
Hunnam dropped out of playing Christian Grey weeks before filming was scheduled to begin

Nearly a year on and the 34 year-old actor is still finding himself having to explain why he suddenly exited the movie adaptation of E.L. James' erotic best-selling novel, most recently he admitted to bowing out of the role because of scheduling conflicts that caused him to have a "nervous breakdown."

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"I wouldn't have signed up in the first place if I didn't want to do it," the 'Sons of Anarchy' star told Moviefone.

At the time, Hunnam received a large amount of negative responses when he agreed to play the lead male role and this was believed to be why he initially left the production, but he insists this wasn't the case.

"I was going to finish 'Sons' at like 11 p.m. Friday night, get on the plane Saturday morning to Vancouver for 'Fifty,' missing the whole first week of rehearsal and start shooting Monday morning," he added. "And I was going to shoot that film, wrap that on the Wednesday and the following Monday I was going to start shooting 'Crimson Peak' in Toronto. I just had like ... frankly, something of a nervous breakdown."

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The upcoming movies' producers had to settle on a replacement to star alongside actress Dakota Johnson's Anastasia Steele fast, and they eventually picked Irish actor/model Jamie Dornan.

Fifty Shades of Grey
Dornan as Christian Grey in the movie adaptation

Mainly due to director Sam Taylor-Johnson's vision of Christian Grey, Hunnam was initially very excited about the role, but when realizing how big the movie is going to be, he felt he couldn't please the book's huge fan base and switch into the character overnight.

"Fifty's going to be massive, it's going to be huge," he continued. "I really didn't want to fail on such a grand scale and I just couldn't transition from Jax Teller to Christian Grey in 48 hours. I bit off more than I could chew and it was painful. I loved the character and I wanted to do it."