Bad dreams...help wanted!

I keep having bad dreams! As a counselor, I would say that is one characteristic of having Post Traumatic Stress Disorder. I haven't had any traumatic experiences that would warrant this type of dream. Last night's dream alone consisted of robbery, shooting (seeing other people die and me getting shot at), explosions, running from scary people, helping an injured cat, heart attacks and surgeries, etc. What in the world? This happens at least four times a week on average, although not always as extreme. I don't watch violent tv shows or movies for this reason. I even turn away when it is a violent commercial. I may just have a very wild imagination but I'm wondering if anyone knows anything about certain foods that cause this more than others...maybe caffeine or something. If you know of any tricks, let me know!