Okay, I've finished the series, and I have something to say: I can't help but relate many of my PTSD symptoms to the stuff in the books. Like in the books, Harry has this mental connection with Voldemort, and when this connection is activated, the former can see into Voldemort's mind. It shows Harry how Voldemort's feeling, and what he's thinking. Sometimes, Voldemort's emotions leak out into Harry so he can suddenly laugh maniacally or show bursts of anger out of nowhere. Harry is told not to let Voldemort inside his mind. I feel this same way with my memories. When I enter a phase of reliving a memory, I can't get out, and sometimes I just feel like I have to shut off this connection to my memories. They can cause me lots of anxiety, anger, and stupidly enough, happiness.
There was another thing: the dementors--beings who suck all the happiness away from a person until there's nothing left. My memories are like that, too, and I'm finding it difficult to ward off my memories. Sometimes, I try to think of happy moments, then I feel stupid afterwards for trying to summon a Patronus that doesn't exist.