Hi MeXoXO.
Something like this is hard to process and it can trigger the ptsd to re-experience a feeling of powerlessness. And you must have cared about this person which does make it personal.
Instead of picturing disturbing things commit to seeing this person at peace. This is how you gain some power over the helplessness you feel. It’s ok to feel sad and grieve to a point where you accept this loss. (((Hugs)))