This is actually a short psychological horror
Even so it's poorly executed. Psychological horror to this degree can't be fully captured in it's depth in a short story in my opinion if it was just plain horror I can see it working.
The real problem here is the lenght of the history, it does not give us time to have some feeling about its characters or make space to “understand” them . But it still a psychological horror, even thought it, indeed, has more of the horror factor
Killing stalking minus the actual psychological horror and just rape.