Accepting that you saw those that suffered bad times, IMO most people in society never see a person die, never suffer more than a bit of bullying at work etc. Yet they still need alcohol, drugs, think they are hard done by.
As a nurse I saw a number of people die, but it wasn't at all stressful- just part of the life cycle. The patients with the least difficult problems were usually the most difficult to look after, and the ones that were the worst off the easiest to look after.
I had more agro from bullying managers than patients, though the relatives were sometimes nightmares.
I did "burn out", but never thought I had PTSD. However, it was a happy day that I retired and never regretted leaving it. Too many bullies to love it.