Dreams from which you wake up with a sense of unhappiness, regret and nostalgia for the past occur for two reasons. The first is to compensate for unhappiness in your present circumstances by reminding you of past happiness and the possibility of enjoying that kind of happiness again. The second is to help you come to face up to painful memories and come to terms with the past.
If you were awash with homesickness in your dream, try to pinpoint exactly what it was that you were missing. The answer may tell you what your unconscious has identified as lacking in your real life. Perhaps it was a sense of belonging, a sense of fun or childhood innocence and spontaneity.... The Element Encyclopedia