[Doc Faustus]

Situations where characters do nothing but run from monsters is bad for characterization, a bad way to set a story up and generally not that scary. Look at the great monster movies and see how soon the characters in them scream "ah, zombies!" and get running. I think you need to read better horror fiction and watch more horror films. Being no doubt a person who has indulged in the digestive process, you should know that what you put in changes what you put out. If you want to write horror, read it. Read Lovecraft, Stoker, Robert Chambers, M.R James, Poe, all of them. People running from zombies is not especially horrific. It's where the zombies come from and what they represent that make things frightening.