Ex-Stag Andy Cook grabbed an 87th minute winner and Clough said: “We did not defend well enough today. You score two goals at home you are entitled to get something from the game.
“We should have kept going forwards after the second goal but we took a bit of a step back – I don't know why.
“Two goals was enough in the previous two games which we won, but not today as we defended so ineptly, especially down the right hand side with Hewitt and Rawson. That's where all the problems came from.
“People just didn't do their jobs and I am angry.”
He continued: “I probably picked the wrong team today. I should have played Kellan Gordon being at home. That was a mistake on my part.
“I think Elliott Hewitt played at Grimsby with the lad that scored and made the third goal and they are obviously very good friends as he's not tackles him all game!”
Clough did concede the game was a fantastic view for the big crowd.
“First and foremost it was a brilliant League Two game with us attacking for the majority of the game,” he said.
“We didn't create too many clear cut chances but we scored two brilliant goals.
“We lost George Maris injured just after half-time which is always a blow as he is one of our main players, but Ryan Stirk came on and did well.
“George has a very sore knee. At the time I did not think there was anything wrong with the tackle. But having see it back it was very close to being a red card.”