It's more normal to have good dreams and nightmares.
Dreams can't express anything and can't predict anything. We should not explore the meaning of dreams.
On the contrary, we should think about how to make ourselves have a stable and beautiful dream.
Reduce unnecessary stimulation, and watch more healthy and relaxing videos or novels in peacetime.
Try to watch less movies or novels that will form nightmare scenes, and avoid bad stimuli stored in memory.
Sleep should relax the brain and avoid excessive excitement in the cerebral cortex.