I'm doing an analysis of the book Misery by Stephen King. Im a bit stuck on the characterization of Paul Sheldon and Annie Wilkes. I was wondering if you had any good tips or knowledge about these two interesting characters.

While Paul Sheldon is the protagonist of Misery and Annie Wilkes is a fearsome antagonist, Stephen King gives her a number of traits that arouse the reader’s curiosity and, at least temporarily, encourage a degree of empathy with her. Much of the novel’s suspense derives from wondering whether Paul will escape his predicament, and if so, how. But another part stems from trying to figure out Annie’s motivation and back story: how does a woman get to be so evil?
In most respects, Paul and Annie are very well matched. King presents characters through contrasting elements that are almost perfectly balanced, especially at the broadest level—male and female, good and evil, captive and captor, writer and reader. As Paul’s “number one fan,” Annie identifies with the character Misery and sees herself as that woman’s advocate; in her perspective, Paul is a villain for wanting to kill off Misery. King also develops their characters through exploring the blurry line between fact and fiction.
Paul must (at least superficially) obey Annie’s orders to save his own life, even as she “mothers” him—King’s ghastly parody of maternal care. Within the infantilized, passive state she imposes on him, Paul must use physical action to build strength and apply his intellect in the real world to a far greater degree than he had to do in the fictional worlds of his creation. Annie’s monomania and hubris initially blind her to Paul’s ability to thwart her plans, and her fury at being outwitted impels her to punish him with increasing cruelty.
Although, in the end, Paul rescues himself, the elements of role reversal help make the novel more than a simplistic melodrama. The reader is left to wonder at the price both characters pay—Annie with her life, and Paul in becoming the perpetrator of violence rather than the victim.