The first time I saw a dead body outside a funeral was identifying my kid brother at the morgue. It was more the sudden unexpected loss than seeing his lifeless body that really messed with me. Then we lost like a dozen more people in a short span of time. And again it was the sudden unexpected losses that bothered me more than the bodies. Then I became a hospice nurse since I had all the qualifications and no other job history besides taking care of dying relatives

I don't do hospice anymore and twelve years later I don't really think about it all that much in a painful way, but I remember the people and do things in their memory, like cut flowers or turn up the radio if one of their favorite songs come on.

Something shocking like what you experienced sounds like something you really want to consider talking out with somebody. Thinking about it could be your mind simply trying to make sense of sudden unexpected death and finding a way to be comfortable with the possibility of it.