Visions?

I get these horrible dream-like things rarely. I will be doing alright in the normal world, and suddenly I will be in some other dimension.

The last time, I was just standing in the shower, and I heard this crow caw behind me. I looked behind me and was in a cloudy, dark desert. I was strapped to the ground in heavy leather boots, and a muscle car was fast approaching me from a distance. I tried to move but I was stuck, hoping and praying that the car would steer away. It continued to come straight at me. I had only one escape, I had to saw thru my legs. I was sick to my stomach thinking about it. I could no way bring myself to do it. I was hopelessly watching my death approach me. There it ended. I returned to my shower with an awful feeling. I can feel it now just thinking of it. I hadn't died, but this was one of my worst visions, almost as bad as some of my nightmares. I think the ultimatum of sawing my legs off came from my body telling me not to cut myself. I had the night before, it felt absolutely wonderful as usual. But I hated the scars that morning, they were disgusting. I had to wear a flannel at the breakfast table so my mom wouldnt see them.

Should I be worried? Ive had other 'visions' before but this was by far the worst. I usually couldnt remember a vision after it happened by day 2 or 3, but this happened last monday and I still cant fucking get it out of my head. Does this happen to anyone else? What can I do?