Well, when the brain gives post-porn twitches and fits in the forms of sexual fantasies and wet dreams, they often do come from rather dark places.
How and why, I have no idea. Sometimes dreams are just sense memories from the prior day, and it could be as simple as you read a news article about a pedophile, and it came back to you in dream form. Put that in the same "stew" as porn withdrawal, and you get something pretty gnarly.
I'd avoid worrying about this existing deep inside of you, though. Thinking that we have all of these horrible sexual things in us wherein we need porn to tell us the truth of ourselves... well, those are lies given to us by porn. The porn industry has fed that lie for a long time that we need to "explore", or else all that "repression" will destroy us. We know that to be false, but sometimes we need to remind ourselves of it. Convincing you that you are, in fact, a partaker in that form of sexual pleasure that you find most digusting... that sounds like a classic porn move. I know you've been on these boards a lot, and I'm sure you can think of some other people posting similar things about their own journeys.
Porn is so full of lies and gets so deep into our heads, it never ceases to amaze me. If it isn't too cartoonish for you, it can be helpful to imagine porn in a personified way... a wicked person who just wants you to feel awful and to think you're way more in need of constant kink to survive. Think of the nasty stuff the little girl says in The Exorcist. I swear, that is what I hear to myself sometimes when I read stories on here about how horrible people think they are because of porn. What else could such a hateful being say to you to get you to despair of a better life free of porn?
Also, I'd also add that the couple wet dreams I've had in adulthood didn't really have sexual dreams associated, except that I seemed to be vaguely aware that my body was going through those motions. There were no sexual arousals from the day, no "peeking", nothing. The dreams weren't flashbacks. I'm not sure I could read anything into it if I wanted to.