Relating Fear, The Uncanny, And Monstrosity

My AP English teacher assigned us to write an essay following Freud's The Uncanny as he breaks down the story of Hoffman's "The Sandman". We are allowed to select our own short story, novel, movie or whatever to relate how Freud's the Uncanny is applicable to our selected literary device. I Chose Stephen King's "The Boogeyman".

My problem is that I have been told I cannot generalize and that I need to include quotes to back up what I am saying. I understand how to use quotes from the story, but how do I avoid generalizing? What other sources can I use to write my essay? HOW do I go about writing my essay? The prompt is:

"How does fear emerge in your example, what is deemed frightful by the writer, and what does this suggest about monstrosity?"

In other words, avoid making blanket statements about literature in general. Instead, make specific statements about your story, backing up every point with at least one quotation that proves what you say. This is fairly standard practice, or ought to be, when writing a literary essay. If you write up a draft, you could post it here for more detailed feedback.