Chiles left the BBC in order to front ITV's morning show alongside Christine Bleakley, only to endure poor ratings and frequent criticism.
He told The Guardian: "I felt in my water that it was going to be a storming immediate runaway success - I was absolutely sure. And I was completely f**king wrong."
However, the 43-year-old, who also fronts football coverage for his new employers, has vowed to fight on in order to rescue Daybreak.
"We've only been doing it eight weeks," he said. "Who quits anything after that length of time? And it kind of feels like it's getting better already. You feel like it's us against the world at four o'clock in the morning. We're all in this together."