We are in a similar situation, and we have to turn on a night light before we dare to sleep, but I don’t have nightmares.
I don’t know if you have been stimulated or feel insecure. Let me tell you a method. I don’t know if it will work for you.
1. There are those sold in the street market. The peach core that children bring is the kind tied with a red string. People say that this kind of thing can ward off evil spirits. Or if you put a peach branch next to the bedside in the room, it has a calming effect.
2. Download a scheduled music player on your mobile phone and download some light music, such as Beethoven’s piano music or others. The wedding in your dream is quite good. You can listen to it and set the timer before going to bed. Well, the music will stop when you fall asleep and it won't disturb you while you sleep.
3. Use warm-colored lighting in the room, which will make you feel warm. A light lavender scent in the room can also help you sleep.
If you have nightmares due to some kind of shock, I suggest you see a psychiatrist. To untie the bell, you must also tie the bell to find out the cause. Hope this helps.