Actor Ben Affleck credits his wife Jennifer Garner for being a calming influence on him whenever he feels the "terror" of starting a new project.

Even after so many years of being in showbiz, the award-winning actor-filmmaker gets a feeling of "terror", which he finds "motivating", reports femalefirst.co.uk.

"That terror when I'm about to start something can be motivating. It helps me kick my a** into gear, because I think, 'Oh my God, I'm gonna ruin this movie, I'm gonna not know what to do'," Affleck told The Sunday Times' Culture magazine.

"That's definitely a good, driving factor for me. My theory is that once you lose that, you're kind of going downhill...(But) it's very trying for my wife.

"She's incredibly supportive and kind and patient with this, but I'll get into this thing of like, 'Oh my God, it's a f***ing disaster. This doesn't work, that doesn't work, I don't know what the f**k I'm gonna do'," he added.

Garner stands by him all through.

"She'll just say, 'You said this on the last movie. You said it on the movie before. This is the point at which you go in there and listen to one song over and over again, and rewrite the scenes you don't like'. Then it's almost embarrassing, because she's so on the money," he said.