Hey!
So, I'm big on Youtube horror niche and know exactly what you're going for. Some quick advice - it's gonna be tough to get 100% copyright-free in this niche, a lot of it depends on images and video that aren't 100% clearable legally.
That being said, I'd love to chat more with you about this but my rate would be $50/video, $20 is too low for me especially if I'm providing the voice-over.
Let me know, thanks! :)