Keep having the same bad dreams!?

Okay I have been having this same dream for about 5 years. Its always about this guy trying to kill this girl (This might sound odd but I think the girl is already dead because I had a dream that he killed her) but when I have this dream it's like I'm seeing something that has happened.The dream is always in the day or night time(mostly day) and it's very hot.So my guess it summer. I wake up sweating really bad over this. All i can get out of this dream is that he wants her dead. When I look at this girl I can't really remember what she looks like. When I look at the guy I can see he face a little he's a white male about 20's or 30's black hair and always wears sunglasses he has shorts that look like they use to be jeans and he's really ruff looking and always has a toothpick in his mouth. He drives an old red van driving around looking for this one girl and when he finds her the chase begins. It's like a bad movie in my head and I don't think it is. I wake up scared and crying over this. What should I do. This is not a joke