becoming more efficient

I was talking with a writer friend recently and discovered to my horror that she had spent 18 hours a day for three weeks working on her last novel revision. I cannot do this. I have been tracking my hours spent writing for the last four years, and the most I have ever spent in one day is about 6.5 hours. I can do that for about one week before I start to throw up at the sight of my computer. 3 hours a day is my goal. I don't know if this means I am lazy or that I am super efficient. 15 wa