Post-Traumatic Stress Disorder
It is not uncommon to experience symptoms of post-traumatic stress disorder after having lived through a situation where your safety was threatened (abuse, assault, natural disaster, etc.) or you were a witness to these events happening to another.
If you find yourself reliving an event in your mind, having nightmares about the event, avoiding places/people/situations that remind you of the event, or have begun to experience high levels of anxiety, it is possible you are experiencing post-traumatic stress disorder. Counseling can help decrease these effects.