Goals from John O'Sullivan and Romuald Boco gave the visitors the win at Meadow Lane on Saturday, which was greeted by boos at the final whistle.
"We just can't get going at home and if we are to be up there at the end of the season then we need to put it right," O'Connor told reporters.
"It was a bad day at the office and every team has them but we haven't given the fans a home win this season and that's the most disappointing thing.
"We now need to show some character against Cheltenham next week. It's still early on in the season and we still have time to put it right.
"The fans had every right to boo because that was awful. But it's done now. We will look to next week and try to get on an unbeaten run again."
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