Mike O said:
But I can stop repeating what I heard in my head, over and over, like a CD on repeat, racking through my mind.
That’s a sign of anxiety. What you’ve gone through is a kind of trauma, and that’s your mind’s response to it. Other people have experienced this response too: it is not something that is unique or abnormal about you. It is important that you know that.
The repetition that you are describing has stopped for other people, and it can stop for you too. But you will need the support (and care) of others. Above all, you need to allow yourself plenty of time to recover.