Intruder, weapon won't fire. What does it all mean?

I had a very realistic and disturbing dream about a week ago. I was asleep and I suddenly wake up. I look over a see a man (mostly a silhouette) and he is very very tall. Hes just standing there in my door way looking at me. I see almost tentacle like appendages coming out from his back and he starts to walk towards me. Im in total shock and awe and look over at my nightstand to see a pistol. I pick it up and start firing....but it never does. I just kept pulling the trigger as the man got closer. I remember the clicks for the gun being very loud and feeling a great deal of hopelessness. The man is now in my face and i see that he has no mouth, ears, eyes or nose. I look up and see a tentacle come down and spike into my skull.

I woke up so scared, i even looked over at my doorway for about five minutes. I was sweating alot and i didn't go to bed for like an hour. What does my dream mean?