Need help starting my essay---have done all the background work/analysis, but feel blocked on how to actually get it formed into an essay...

Do you know what you want to say? If not, you probably don't know anything about it.

Make a 3-5 bullet chart, write down something important on each. then put it away, and come back in a few hours or the next morning, and you should be able to decide what you want to say.