I am so sorry you experienced this. I've lived with chronic nightmares and chronic night terrors for many years. Frequently my husband has to shake me awake because I'm screaming uncontrollably. He dislikes doing this because I also suffer from chronic insomnia and rarely sleep. Let me share with you a couple of things that have helped me.
First, usually most aspects of what I dream are rooted in insignificant things that happen during my day or things I'm concerned about on an "low level" - not exactly subconsciously but I'm not dwelling on it. The other night I had a long, crazy dream my kids found hysterically funny because of all the bizarre clues hidden throughout it - from the thawing poultry pieces (because my homesteading son and daughter-in-law had recently butchered a chicken) to another daughter making her movie debut in a ballet video (because I'd been looking at a ballerina doll on my granddaughter's bedroom shelf) to me burning fish sticks (something I never buy but had seen a TV commercial for Arby's fish sandwich). This was not a scary dream and it was filled with quirky, funny stuff that we could pick out why it was all in there. My terrifying nightmares are often the same way. I've obsessed about some past hurt or betrayal, had a new flashback, or relived a horrible trauma. Once I figure out what has triggered the upsetting elements of the nightmare, I usually can calm down a bit.
Second, with my comical dreams, we never attach any significance to them. At face value they are meaningless "movies" played out while I'm asleep, often based on trivial incidents that happen during my day or thoughts that may have crossed my mind. They may be interesting, but they have no intrinsic meaning.
Lastly, we are not prophets or visionaries. Those of us with emotional issues may be a bit quirky around the edges, but we certainly can't predict the future. Our dreams and nightmares are exactly that. Some may be bad or even terrifying, but we need to calm down and logically recognize that what we experienced was a frightening nightmare and everyone has them.
I'm not trying to make light of your nightmare. I know how terrifying they are. I've knocked over lights and broken lampshades during my worst ones. My doctor says therapy will never work for me because I "think too logically." I need to approach my nightmares logically in order to deal with them. Maybe it will work for you, too.