There are a wealth of writing tools on ye olde internet to get you started. I like using prompts sometimes to get me going. You can find a TON of horror prompt idea generators in cyberspace. I also enjoy using photos or paintings as prompts. Find a creepy photo of a desolate barn or something and then imagine the horrors that lie within.
So yeah..you still have two weeks to get your spooky on. Plenty of time to wrestle your inner demons onto the page and add spooky sound effects.