Maybe in reality you are unconsciously anxious/nervous/afraid about something. Like putting yourself at risk over something or you are in the middle of a chaotic situation. Maybe. I believe that when we are asleep, our inner consciousness are alert. Strange dreams does not usually means an omen but can be interpreted as your true personality's yearnings and sufferings. There really are many form of dreams and ways to understand it. Like an over reactive mind that doesn't sleep and keep spinning thoughts that sometimes triggers the emotion; even when you are physically asleep. That is perhaps why people wake up afraid or in tears. As i said, there's a difference and a different way of understanding it.