There is a med called Prazosin that can help with nightmares and early wakenings due to anxiety dreams/nightmares. I tried it for awhile and it did seem to make a difference. It is a blood pressure med and I'm on the lower side of normal anyways so it did have a physical effect on me, but it's pretty harmless!

Also I find that limiting your exposure to certain things might help.. such as video games and violent or gorey types of TV or movies. If you are exposed to a lot of violence or are a vet or what have you, the images of people dying or torture are not so readily processed by our brains.. Like your brain just can't make sense of these things. I know how hard it is to deal with this. After I did a stint on prazosin, I was left with anti-anxiety drugs which seemed to work to keep me asleep and not wake up in a panic from dreams or a physiological reaction to stress or anxiety (waking up with your heart beating, gasping for air, jumping out of bed..)