I'm not sure how to answer this from a spiritual standpoint, but if you want to work on treating the nightmares, this article has some good supplements: Nutritional influences on sleep - Nutritional Influences on Illness Townsend Letter for Doctors and Patients - Find Articles
If you don't take a multivitamin already, it might be helpful. Also, a B vitamin supplement or magnesium supplement may help.
These are good to start with, and they're inexpensive: Calcium and Magnesium with Zinc Mineral Supplement | Nature Made | Walgreens Stress B-Complex with Vitamin C and Zinc | Nature Made | Walgreens
You may also want to do a Google search for insomnia treatments if you are having trouble sleeping.