"We just didn't get out of the blocks; we had a sloppy start and it carried on for 90 minutes," admits Kevin, who once more came into the action from the bench as Alan Pardew started with a wing back system.
"At one goal up they camped in and did a great job on us and restricted our chances; give them credit but I thought we were terrible.
"Everyone that was involved, including myself when I got on in the second half, didn't perform the way we should have.
"We are bitterly disappointed as was the crowd - and they have every right to be.
"It must have been absolutely terrible to watch and we have to learn from this - we realise it is a very important season for us."
Kevin admits the result - and performance - puts pressure on the home game with Sunderland and he adds:
"Saturday is a massive game for us now; Sunderland are a good team and are going to be coming to our place thinking they can get something out of it.
"We realise no one's place is safe for Saturday and whoever gets the shirt will have to work their socks off to get that result."
As for Alan Pardew's reaction to the players, Kevin reveals:
"He said quite a bit to us that can't be repeated - that obviously stays in the dressing room.
"But he was bitterly disappointed and as professionals we have not performed and let ourselves down - and everyone that has come to the game.
"But there is only us that can change that - and that is basically what he said, that whoever plays Saturday has got to work hard and help us get the result."
As for the fans' vocal display of disappointment - and not forgetting that Kevin himself is a Hammer - he says:
"It is expected; when you don't perform you expect to get the boos and they pay good money so they have every right."