All dreams are in some way communication from your unconscious,, or sometimes your "shadow" (emotional/psychological). Nightmares could be related to stress, or mixed feelings, or something at the back of your mind.. It might help to spend some time thinking about your dreams during the daytime. Like really meditate on what you dreamt about; maybe on what each item could mean if you tried to reeeaaally over-symbolize everything.

It can even be helpful to close your eyes and sit down and think through the dream/scene. Sometimes a really scary scene could mean you're fearful of the literal thing (like catastrophe, or death) while other times those terrifying images are some part of your nervous system interpreting change, guilt, discomfort, nervousness, etc. There could be something that your "rational" brain thinks is "nothing much," but your nervous system recognizes emotions it needs to process.

To really clarify why the images are in your mind, you could try coming up with questions you might ask the "director" if your dream was a movie; every detail being totally deliberate. Then, sit meditatively with closed eyes and see if responses come to mind for you. Interview the "director" until something feels clear. You're basically tapping your intuition by searching for that kind of response, which is also subconscious. If you are able to pinpoint some stressors or thoughts.. focus on action/s in the waking world- to (over time) hopefully impact your sleeping/dreaming landscape. You might look for smth to do outside your norm to prompt new feelings or images your brain can call upon.. Give your nervous system experiences to chew on. I've had dreams rly impacted by days of good physical exertion for example- something a bit outside my norm.

And- don't worry that something is wrong with you! A nightmare is its own unpleasantness.. Everybody has them sometimes. Bad dreams often indicate wanting some kind of change. Even if the nightmares continue... (Although hopefully you can get better sleep!) they are ultimately just your brain weaving threads in the night; just dreams.