Classic PTSD.
You go over and over and over the event, replaying the movie in your head from one angle after another, until you exhaust yourself from repetition, yourself but not the movie, 'cos there's always more angles in your fertile brain. Until you've worked it so often it's like smooth worn stone, and you're sick to fucking death of it, and of yourself.
But that's how it is. It isn't personal, reader friends. It's baked into the brains we've inherited since aeons. It's what we do, when there's trauma. We spin around inside our confusion like old socks inside a tumble dryer. I have no idea what that simile actually conveys, but I like the image.