The 65-year-old is still without his first win at Loftus Road since taking over a fortnight ago, and admits he is feeling the pressure of his new job.
QPR have remained winless for a Premier League record of 16 games this season and are eight points adrift of safety.
|PREMIER LEAGUE LATEST
|2/1||QPR are 2/1 with Bet365 to finish bottom
"I've got stuff on my mind and it's not been easy [to sleep]," he told the Evening Standard.
"I was sleeping very well two weeks until I came back to work. It's more difficult because you're lying there waiting for that alarm clock to go off very early.
"You're thinking what you can do, how you can improve it, what's the best team, who can play where? It's a tough job."
But QPR captain Ryan Nelsen feels the team’s performances have improved under Redknapp, and insists they should take positives from their last couple of games.
"I think we've been a lot better. We've had two awkward away games and got points out of them, so we have to take the positives," Nelsen added.