well it is both...the incidents are triggering the past trauma so you are having a traumatic response as a result of the triggers. triggers are anything that illicit a response from you that would not be "normal" from an encounter with that particular stimulus. it appears you have been really traumatized by your boyfriends indiscretion and may be accurate in assuming it is based on your past. have you looked into professional help to assist you in working through these issues?