Holbeach United boss Darren Jarvis had “mixed emotions” after grabbing a draw from 2-0 down on Saturday.
But he promised to make changes unless the Tigers improve soon.
Jarvis said: “On one hand I’m almost thankful with a point.
“That’s no disrespect to Northampton Spencer who came here, battled well and worked extremely hard.
“However, we have got to be disappointed with ourselves. In the end we were very lucky and we got out of jail.
“We’ve got a lot of good footballers so playing a good game then a poor game is just not acceptable.
“They have let themselves down. I feel they have let me down but most importantly they have let down the club and our supporters.
“There are peaks and troughs. It’s all very well having a great atmosphere in the changing room but that counts for nothing because I came here to win games.
“I’m not here to pick up a point against teams like Northampton Spencer.
“Emotions will run high during and after games but ultimately it’s unacceptable – full stop.
“I was thankful when Chris Ward didn’t get sent off for their penalty, although it was a 50-50 call. If I was in the opposition dug-out then I would have been screaming!
“I felt that on the whole the referee handled the game well and most of his decisions were right.
“We’ve drawn the game and I feel absolutely gutted.
“I know I’ve got to take my share of responsibility and perhaps I’m not doing my job. We should be getting three points from these games and I’m terribly disappointed.
“Too often I’m saying it’s not acceptable. So we need to put things right very quickly. We owe that to the club and our supporters.
“I’m not here just to have a good time. I want to to win games of football.
“I’m getting frustrated and the players know that.”
Jarvis is demanding a positive response from Holbeach at home to Harrowby United on Wednesday night – but admits to feeling “sick and tired” over inconsistent performances.
He added: “I’m getting very frustrated at having to ask for a decent reaction from the players after every other game.
“They need to turn up with the right attitude and approach.
“If things don’t correct themselves very quickly then there will be changes.”