EDGAR Davids said he was becoming increasingly frustrated with mistakes which are costing his Barnet side dear.
Their 1-0 defeat at Cheltenham Town on Saturday left them rooted to the foot of the League Two table.
Things went to plan for the London club in the first half, but Jeff Goulding's 80th-minute winner was enough to earn Cheltenham the points and Davids said his patience was running out.
"You can see the positives, but you have to look at your own mistakes and work on that because it's getting annoying," he said.
"It was hard to take, but we have to take it on the chin and try to play better next time.
"You play a top side and we could match them in the first half. In the second half, we let is slip a bit and they showed they are a very good side."
Davids said Barnet could take heart from their first-half display as they gave as good as they got against third-placed Cheltenham.
"It was a very good first half and that gives us inspiration for the future," he said.
"We had some little chances and a penalty. They had a couple of chances before that and they played really well.
"We were prepared, but we not prepared enough, so we have to make sure we are better in the future.
"We will train on certain aspects, but we have finished the first phase and now we are going to the second phase of my time here."