Literary Pressure

I'm working on the last 80 pages of my novel. It needs to be in by Wednesday. I thought this would be a breeze, but I just spent three hours rewriting three pages! I'm not a perfectionist, but I kept trying to get just the right feel to a scene. All because of an editor's note in the margins of the page, that read: "I guess I don't know where this is coming from." I thought the purpose of the scene was clear, but I was wrong. So, I'm clarifying. All last week was about cutting, now it's about fleshing things out. A simple comment from my editor like "This character needs more motivation for him to react this way" caused me to go into a late night writing fit finding more motivation for a character to do what he does. Ah, the writing life.