Like Mauricio Pochettino, Harry struggled to come to terms with the 5-1 loss against Newcastle on Sunday.
“It's left a very bad taste,” admitted Harry. “The first half simply wasn't good enough.
“We did the hard work getting ourselves back into the game, they went down to 10 men and then we conceded three.
“That was probably the worst performance as a team I've ever been a part of. There are no excuses. No words can put this right.
“We apologise to the fans. We will have to take it on the chin and start again next season.”
Below: Harry speaks to Spurs TV at St James' Park
Yet it’s there in black and white - third place is our best-ever finish in the Premier League, and best since 1990.
“We've had a fantastic season but the last four weeks haven't been good enough,” conceded the striker.
“It's hard. It will be hard for the fans as well but the bigger picture is that we're playing Champions League football next season which at the start of the season any one of us and any fan would have taken.
“It hurts now and I'm sure it will for the next few weeks but we're back in the Champions League next season and moving forward.”
It should have also been a day of personal celebration for Harry, who secured the Golden Boot in the Premier League with his 25 goals.
He becomes the second Spur to win the Golden Boot after Teddy Sheringham in 1992-93 and only the 10th to finish top scorer in England’s top flight, going back to Bobby Smith in 1957-58.
Presented with the trophy at St James’ Park, Harry struggled to even raise a smile.
“It's nice to win it but it would have been nice to win it in different circumstances,” he added.
“Winning today was the most important thing so we feel like we've failed and that will leave a bad taste over the summer but at the start of the season we would have taken it so we have to look at the positives. It's been a fantastic season but the last four weeks just haven't been good enough.”