The Take That singer admitted that he found his first year as a judge tough, adding that he plans to show his "fun" side on this year's live shows.
"I did come close to quitting, yeah. It was hard," he told The Sun. "When you become part of this machine, you're on something that's moving and you've got to try to stay on board. There's no jumping off.
"There's a lot of pressure - it really is massive. I remember last year - on Sunday nights in particular - if I knew one of them was in the bottom two, I'd feel so nervous.
"And you'd watch this spaceship swirling around knowing that millions of people are watching and it was out of your hands, and you'd just feel sorry for them."
Barlow added: "I just want to have more fun this year - and I have done already. I was on tour while we were doing the auditions last year and it was bloody hard work.
"I always felt miserable when I arrived because I was knackered already. But this year I don't feel like I've done anything yet! It's been fun."
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