Help Understanding Dream

So, I have just awoken after a rather odd nightmare. Well it started off me going to my girlfriend's house. I walked down her street, have her a hug, and we then we got on a train, to go to a nearby town. We have been there before, and I recognized it instantly. We held hands and walked into the town, and found a plaza. One on both sides of the street. She walked off to go into a store and I found a man with a clean-pressed black suit, with no hair, no face, walk toward her. I'm not sure what happened next, but i panicked and yelled her name, and then things got dark, and somehow i was in a hallway. There were 3 doors on the left, 3 on the right. the man stood at the last door on the right. I yelled my girlfriend's name more, and heard her calling me. But i could not see her. The man disappeared. and i went after him but a stairway faded in. it went down. Then i tried opening the door directly to my left, the first door on the left. I do not know what it was, but something made me fall. I fell down the stairs but somehow recognized a bookstore, or library. Then a black hole opened up at the bottom. right before i hit the bottom, i fell off my bed, and hit my head on my dresser. Does anyone have any insight as to what this might mean?
xxhaloreacherxx xxhaloreacherxx
18-21, M
Sep 17, 2012