A Robert Snodgrass goal in the 47th minute was enough for the Canaries to claim all three points, a win that moves Chris Hughton's side up to 14th in the Premier League table.
For Spurs, the loss means they remain in fifth place and trail Liverpool by six points - a defeat that Sherwood has labelled as 'bitterly disappointing'.
"We didn't get started until the second half, which isn't good enough" he told Sky Sports.
"We started brilliantly at Newcastle and we got the rewards - today we took too long, we weren't brave enough on the ball, didn't take enough risk and weren't good enough in our one-v-one defending.
"There weren't a lot of positives in that first half but in the second half we had chances and threw caution to the wind.
"After half-time I had words and said 'we need to go out and be better in the second half' - after a minute they score. It gives them a leg up and gets the crowd with them and it was difficult. We had some clear cut chances to score and if you can't take them you don't win football matches."
Spurs have lost five of their seven league games after playing in the Europa League, but Sherwood refused to use the competition as a reason behind their defeat at Carrow Road.
He said: "It's difficult to make an excuse like that, you've got to give Norwich some credit. There were sprited today and they played well and worked hard.
"It's just bitterly disappointing for us that we're coming away with nothing and we possibly never deserved it."
Despite the defeat, Sherwood remains in defiant mood and insists that their Champions League aspirations are not over yet.
"It's a dent, we're still in it. We're still looking up rather than behind. We've got two home games now and we need to bounce back - that's what good teams do," he said.
"That's what players with real spirit do and we've got to see what we have in there."