This has something to do with your mental state during the day and before going to bed. If you are stressed during the day, you are likely to dream about these things. This is related to the pressure of study or work. I don't quite understand it, but I have experienced it. If you are afraid, don't think too much. Think positive things and listen to some nice songs. If you are afraid at night, try not to go out. If you have faith, pray according to the habit of faith. If you are a Christian, the effect will be better. When you can't sleep or are afraid at night, you will basically pray, and then you will fall asleep slowly and get comfort in your heart. I can only answer so much. I hope you can get rid of these things ~