Thank you for contacting JustAnswer.
I am sorry to hear about the problems you are experiencing. Having been in a relationship with someone who is narcissistic is extremely difficult. You may find this article helpful in understanding this condition: http://www.psychologytoday.com/articles/200512/field-guide-narcissism
It is possible that the nightmares and other symptoms that you are experiencing may be due to Post Traumatic Stress Disorder from experiencing the trauma of this relationship. PTSD is an anxiety disorder that is triggered by trauma from an event or an experience such as you describe. The following website provides additional information about PTSD and may be helpful for you to determine if this may possibly fit what you have been experiencing: http://www.nimh.nih.gov/health/topics/post-traumatic-stress-disorder-ptsd/index.shtml
While I cannot diagnose your condition, it may be helpful for you to see a psychologist who specializes in PTSD in order to determine if this is indeed what you are dealing with or not and to get appropriate treatment in order to work through these issues.
I hope this answer is helpful. Please let me know if I can clarify further.