I analyze the cause of your dream, your grandmother, who wants you to become attached to Buddhism, so this dream tells you that the Buddha's name can gradually relieve your distress.
If you are afraid of people in white, you can also recite the Buddha's name and give it back to people in white. May he be happy from suffering and live a good life (he can recite it many times). You will gradually stop being afraid of him in the future. I wouldn't dream such a terrible thing.