I Have These Dreams That Scare The Shit Out Of

I have these dreams that scare the shit out of me, my psychologist says theyre a product of my PTSD but im skeptical, I guess im looking for a second opinion. In these dreams, they're what one would call a nightmare I guess except that im not scared, It's pure serenity, I've never felt such peace, and this is what scares me. In these dreams I do all sorts of terrible things, such as strangling my mother, or ripping my sister apart with my bare hands. There is one however that is reoccurring and very vivid and in it I am walking thru a swamp but instead of water there is blood, and instead of trees there is bone and strips of flesh for leaves, I feel so at peace in this dream I actually enjoy it and that scares me. If it helps I am currently taking atarax and recently started taking prazosin 1mg. All im looking for is a second opinion. I deployed to Afghanistan but I didn't do much, certainly not enough to have developed PTSD at least not in my opinion. Thank you