Oh, and I'm not sure if you're a caffeine junkie (like I am) but recently I've been having some pretty bad insomnia, so I've cut my caffeine sources after 4pm so that I can get to bed at a reasonable hour. That might also help.
It depends on the content of each essay, but I think it's always good if you can cut down on what you're asking the admissions office to read. If you cover your diversity factors in your PS, you don't need to write a separate DS.