The Candy Stripes suffered their first defeat in 15 games stretching back to last season, but Lafferty now wants City to begin a new run starting at Head in the Game Park, on Monday night.
After taking the lead through James Akintunde's first half goal, the Brandywell men conceded twice in the space of seven minutes on Friday, as Shels' Shane Farrell and Brian McManus netted to claim the points for Damien Duff's side, much to Lafferty's frustration.
"We're all disappointed and obviously to lose the unbeaten run is disappointing but I think our second half performance wasn't quite good enough," he insisted.
"I thought the boys were excellent in the first half but I think from the start of the second half we didn't get going and having been ahead in the game and then to concede two goals is a bit of a kick in the teeth, but it's not the end of the world, it's a disappointing result, but all we can do is recover and get ready for Monday night.
"The word in the dressing room at half-time was that they were going to come out with all guns blazing in the second half, but whether we didn't heed that warning or for whatever reason we aren't sure, but we just didn't get going in the second half and if you don't start halves of football well, then the likelihood is you'll concede, which we did.
"But look a loss was going to come so now it's about how we regroup as a squad and make sure it doesn't happen again on Monday night and bounce back at Drogheda."
City get the chance to bounce back at Drogheda tomorrow evening, but Lafferty is expecting another tough game at Head in the Game Park, in fact, before Shels' victory on Friday night, it was the Boynesiders who were the last team to have defeated Ruaidhri Higgins' men, when they secured a narrow 1-0 home win last October.
"In football you normally have to wait to get a bad result out of system, so we are lucky another game comes around fast and we'll be looking to put Shels defeat right on Monday night," explained Lafferty.
"However, in saying that Drogheda is a tough place to go to. It's a tight pitch, they make it difficult and they'll be hard to break down. But we'll come up with a game plan to try and beat them, so that we can try to bounce back from Friday night.
"We'll be going to Drogheda hoping to pick up the three points on the road, because we have been very good on the road recently and we'll be looking to continue that."
City go into the game with the same squad that featured against Shelbourne, so goalkeeper Brian Maher looks set to miss out again; as for the home side they are expected to be without trio Darragh Markey, Adam Foley and Dean Williams through injury.