I've recently heard of complex PTSD and it seems to make quite a bit of sense for me. It was a lot of various factors that contributed to my PTSD. All the crap I suffered through at school as a kid and then my parents not getting along so I didn't necessarily have a supportive home. Also some things that where more out of ignorance did not help like if the light in a room was painfully bright for me and I mention it only to be accused of complaining for no reason and stuff like that obviously already being under stress from having a hellish time in school and parents too busy arguing or not speaking to each other to pay much attention. So yeah but the worst of that was being ostracized and picked on at school.

then at the age of 15 I attempted suicide, had a terrible incident where I almost got in trouble for something I didn't do and then when I was 17 a student I knew was killed by this random person who came in the school which I certainly did not react well to. So I am sure my PTSD symptoms are caused by multiple experiences.