It is for this reason, I believe, that many people who are secretly interested in writing horror ultimately end up holding back.
When you're brainstorming things for horror short stories or novels, it's really easy to be hard on yourself as far as, "oh no, that idea has been done, bleh." And to a point, of course recognizing if your idea/interpretation of a certain subject has indeed been done is very important.
Although, I do think it's equally important to remember that what you're writing about is not exactly what you need to worry about on that is-this-cliche level. On paper, lots of things look cliche, which leads me to re-acknowledge another one of those widely-heard writerly advices: it's all in the execution.
There are so many cliches in every genre out there, and horror is no different. Certain types of mythos, certain types of characters, certain types of settings and villains and beasties and happenings. And after such a fascinating, incredible history in this genre, it can sometimes feel like everything has been done in every way. As it is, it's so very rare to find something exhilaratingly new in horror, so why try to write your own horror story if it will probably just get written off as cliche anyway?
But cliches can be done in a fresh, interesting way. And with horror especially, many artists are striving to show the audience their interpretation of that escaped mental patient, or creepy carnival, or a cemetery were the dead awaken for Halloween only, and how/why their version is unique in its own right.
So, guess what? The fact alone that you are an individual qualifies you for the possibility of churning out something truly different, cliche ideas be damned. Don't be afraid to scare other people with your story. Don't hold back when you are brainstorming because you have that terrible fear of being, well, fearful.
Whatever scary thing it is that inspired you to "maybe" try horror is relevant. And if you feel like your big old cliche of an idea can be accurately translated to show what scares you (never write to scare the audience, always write to scare yourself) and why in a uniquely told story....
DO IT. The genre could use you!