had nightmares after 23 days. What medicine to...

nightmares treatment 
Nightmares are disturbing dreams accompanied by negative feelings such as anxiety or fear that wake a person from sleep, and they usually occur more often in children, but they can occur at all ages, and nightmares may begin in children between the ages of 3 and 6 years and usually less than after the age of ten, however. About half of adults have nightmares at some time. Here, a distinction must be made between episodic nightmares, which are common and not cause for concern, and nightmares disorder, which is a sleep disorder in which nightmares occur frequently.
The treatment is done by determining the cause, such as avoiding any medications that work on nightmares while avoiding caffeine and nicotine, which helps reduce nightmares, as their effect extends for more than 12 hours in the body, which affects sleep with cognitive behavioral effectiveness of up to 70% in adults who suffer from nightmares Medications, including those caused by anxiety, depression, and post-traumatic stress disorder, may be used in conjunction with treatment 
Prazosin is recommended for treatment of Posttraumatic Stress Disorder (PTSD)-associated nightmares.
or you can use Clonidine  but prazosin is better
Diagnosis
Discuss the symptoms. Nightmare disorder is usually diagnosed based on your description of what you're going through. Your doctor may ask about your family's medical history of sleep problems. Your doctor may ask you or your partner about your sleep behaviors and discuss the possibility of other sleep disturbances, if identified. Or you can do a sleep study at night (sleep test)
What are the causes of nightmares?
Anxiety and stress
sleep deprivation
Some medications, such as some antidepressants
Alcohol and drugs
scary books and movies
Family and patient history
Advice :
  We recommend that you visit a psychiatrist, so that the symptoms can be taken and the tests carried out more accurately