Deeply Disturbing Nightmare, Violence, Sexual Assault: Please Help

I honestly feel strange even posting this but I feel like this dream was so messed up...I need insight and want to know what some of the underlying issues could be.

I've had ongoing nightmares about being pursued, chased, etc. since I was very young. At certain times in my life, these dreams about been more persistent and at others, practically nonexistent.

More recently, these dreams have returned and last night, I woke up sick to my stomach due to the nature of this dream. I'm a working professional, I'm very happy with my life and I'm not the type of person that likes to think or worry about the negative. To my knowledge, I don't have any "repressed" memories and had a fairly normal childhood. Why do these dreams resurface?

Just a warning...this is graphic.

My dream started out where I was in a crowd of people, looking out for a little girl. She was very overweight and seemed to be slightly mentally handicapped. As I followed her, a man continued to pursue her/us. I knew he was evil/malevolent the entire time even though I never saw his face, I sensed his presence the entire time.

At some point, we ended up in a dark tunnel beneath a city. I was still following the little girl. And at this point in time, I lost my ability to protect her. Instead of being behind or beside her, suddenly I was watching her from below. It was like she and this evil man were walking on unbreakable glass/ice above me - but I could do nothing.

It was then that she was thrown down naked and I watched as he put numerous bullet holes through her. She was struggling and crying for help the entire time, but I could do nothing.

At some point in the dream, I ended up finding where this man lives / harms and kills his other victims. I was basically wading through limbs of people he had killed.

I could go on about how graphic it was, the gore, etc. but I'm not sure that it's even that relevant. I don't know how to describe how deeply this dream scared me.

Please shed some light, if you can. I appreciate it.

You were watching some thing going on "Above" you. Some thing you feel helpless about. Look in your real life and try to find what is going on "Above" you that you feel helpless and scared about. You are feeling some thing is tearing you apart. Look both inside and outside to find out what this may be.