Cook made a blunder against Hull that led to a goal and in the defeat to Arsenal last week he gifted the ball to Alexis Sanchez who slotted home for the Gunners.
Cook knows if he is to progress he must cut out individual errors - starting on Sunday in the high-profile visit of Liverpool.
"I'm only 25 but I'm taking on a role I need to embrace and enjoy, but at the same eradicate mistakes to take my game to the next level," he told reporters.
"That's why Sunday hurt me so much. It shouldn't happen, so that's something that has to change.
"As a footballer it's the worst possible thing that could happen. It's difficult to talk about, because emotions change throughout the game
"I've put Sunday behind me but I wouldn't be able to describe the emotions in my head at that point. I wouldn't want to compare it to normal life."