Writing/Reading Horror

I'm trying my hand at writing horror and I didn't know if anyone had any good suggestions for novels to learn from or tips in general for writing horror. Also, they don't necessarily have to be novels, I've been scaning through creepypasta but I haven't found anything too terrifying yet (Ben Drowned was slightly creepy, but the Russian Sleep Experiment was underwhelming).

So far I've kind of identified helplessness and the unknown as major, primal fears that keep reoccurring in everything, but that's a pretty easy observation to draw and doesn't get me much closer.

If I've learned anything from creepypasta reading, it's that you try not to be too unrealistic or accidentally cheesy. If you're going to have something that eats people, don't make it say "That was tasty" or "Yummy yummy in my tummy!" unless you're going for comedic effect. People with no eyes and bleeding sockets seems to be a trope that I think is used too often too.

That's all I have.

Subtlety. Describe a character whose words or actions don't fit with who he is, or have something be just subtly wrong.

I remember I read a creepypasta where there were wierd things, and everything was wrong, and obviously wrong, but it was never clear WHAT was wrong. And it stuck with me for a while, because it was just so FREAKY.

Thanks, guys. Read the really creepy "Pen Pals" series of creepypasta, by far the best I've read. By "best I've read" I mean pants-shittingly terrifying.