No worries if you repeat something, I don't think anyone will mind, especially if you add how you yourself process and respond to specific movies.
I do think there's something to the adrenaline high - adrenaline is what our body releases during our PTSD moments, so to have that excitement in a safe, controlled way can be very appealing for some. I watch some pretty bloody stuff - Saving Private Ryan, Game of Thrones, Oz, etc. There's something about the visceral scenes that makes it extra compelling, and in a way it distracts from one's own pain by witnessing it in someone else. Of course, I'm only OK with that in fiction, not live-action. If I want to see real people in pain, but not feel bad for them, I'll watch an episode of Wipeout. :P