Melancholy in a dream means that the value system of a person is not good, the person wanting to feel disconnected or to be alone. They want some sort of personal validation. Either they are trying to find acceptance with someone, they want to communicate their frustrations or feeling unheard.
It is typically a sad feeling but it can also appear to be depressive and even destructive. When we experience this emotion, we want to feel better. Some people try to get rid of their melancholy through activities – making lists, workouts, drinking coffee etc. Others choose to express themselves artistically in words or other scenes of feelings that help them remove this feeling of melancholy when it appears in their dreams.