The result leaves Lesmahagow fourth and two points outside the promotion places, having played 23 matches.
“We got what we deserved,” Irving told the Carluke and Lanark Gazette.
“We were absolutely rotten, hopeless from start to finish.
“To be fair, Girvan weren’t much better.
“We have probably fought above our weight this season.
“I’ve got some young boys in the team that have got great potential but they’ve got a lot to learn.
“They start arguing with one another and they just lose concentration.
“Myself and Davy Jackson (’Gow assistant manager) spoke to them last week before we played Ardrossan.
“We said: ‘Before you go on that park, you have got to concentrate 100 per cent. You can’t start arguing with folk’.
“Then two of them started arguing in the warm-up and you’re just shaking your head.”
Irving – whose side visit Greenock in the league this Saturday, KO 2pm – is hopeful of making some new signings over the next fortnight.
“You can sign professionals up until the end of March,” he said.
“But it’s finding them. You speak to some boys, you hear your wage demands and you wonder if it’s Man City or somebody they’re coming to!
“It’s crazy the money they ask for.
“We are down to the bare bones. And I have a boy away on holiday this weekend and I’ve got Jordan Whitefield out injured and Kyle Weir out injured.”
Robert revealed that recent £500 signing, striker Jordan Kemoe, has left the club after only four weeks as he’s gone to visit his family in Cameroon.
Kemoe had previously starred for Partick Thistle youth team and Cumnock.