How do you get rid of nightmares?

I have been having continual night-mares for about a month. They usually revolve around death or something trying to hurt me. Last night I had a dream about the holocaust and that I was at Auschwitz. I am 22 years old and live in AZ, and have never been to Poland ever. I am student teaching currently and under much stress with the economy and thinking about looking for a job. Also, I have been using a steroid nasal spray for allergies the past few weeks. What could be causing these nightmares and how do I make it stop???