All I have to say is this. Many of our dreams are conscience dreams. Meaning...its responses that is influenced by our environments. Though we dream about things we may of never think we witnessed or experienced. This is because when we dream all of our brain functions are being stimulated in a deeper conscience. Thus including the part of the brain function of imagination. which would create new ideas from what already exists. Our imagination is obviously a strong tool of the brain used in our dreams.

If you are having dreams like that. I would question what is in your environment and seek ways to change that. Because obviously its not good.

I know for myself when I was in a cult as a child. They spoke many things that I realize today are not true. Even showing movies that were terrifying, that was not necessary.
I had nightmares and developed an unreasonable fear and confusion over it. Later on in life. I realized it was just a twisted environment. When I was separated from that environment my life veered away from that confusion. ...Well until another tragic event happened in my life.

Not sure if this is helpful. ..but just trying to give a view point from my experience on the basics of dreams.