How do you move on from a family murder?

In 2013 my brother was brutally stabbed to death by his own son. The story is long and not really something to explain in a post, but my issue is. He was stabbed to death and though I wasn't there I can see it. I can visualize it. It happened at his home, which used to be my grandparents home. It happened by another family member whose face if familiar. I can see it. I can hear it and right after it happened I could almost smell it. On top of that I made the huge mistake of reading the autopsy report because I was trying to get the details of his tattoos. I'm a nurse and understood it all too well.

If I see anyone getting stabbed on tv or in a movie I can't sit through it.

It has been 7 years. While I have accepted his death. I can't move past these things. So maybe this is some form of PTSD even though I wasn't there?

I'm sorry you are still struggling with this tragic event. I can't honestly say I can relate to what you experienced. But many years ago I worked in the emergency departments of two different hospitals (plus a stint in the O.R. of a third. So I saw, & dealt with, my fair share of death. Some of the images still come back to me from time-to-time all these many decades later. I'm not a mental health professional. But personally I would say what you've been experiencing certainly could qualify as PTSD.

Here are links to 4 articles, from PC's archives, that (hopefully) may be of at least some small bit of help:

Posttraumatic Stress Disorder (PTSD) | Psych Central

Coping with Obsessive Thoughts

Understanding and Coping with Emotional Flashbacks

Letting Go of the Past: Why Memories Remain Painful Over Time

Best wishes...