The Fifers conceded three first-half goals against the Diamonds which in effect blew any hopes they had of taking something from the game.
Dumbarton, who were beaten by Falkirk at the weekend, sit one place above them in the division with the two meeting this Saturday.
Goalkeeper Gallacher expects there to be plenty of discussion about the weekend’s defeat at training this week, but adds that it’s important the players move on from it.
He said: “The first goal kills us essentially and the half goes on to become very difficult after that.
"It’s man v man and they started dragging us about.
"We’re just going to have to stick together now, realise and wake up a bit as a team that nothing comes easy.
"We have to sort it out.
"I wouldn’t say our shape was wrong, I thought it was perfect against them, but they took their moments at key times.
"We had three really good chances and it becomes a different game if you take them.
"We’ll look at the game back and everybody is going to have an opinion on it.”
Attention now turns to Saturday’s crunch game at Dumbarton. Neither side goes into the match in great form, but Gallacher wants his side to rise to the challenge.
"Dumbarton are above us and it’s a massive game for us,” he said.
"We’ll be doing everything to capitalise on it.”