Veterans are the most discussed, but women are the largest subpopulation https://www.ptsd.va.gov/understand/common/common_women.asp

I sometimes wonder if my own PTSD is actually PTSD or if it doesn't count because I'm not a veteran or woman and it happened online.

It wasn't abuse; it was just an extremely stressful social and emotional situation that led to the loss of someone who was probably one of my closest friends, although I no longer remember who.