Honestly, that sounds exactly like mine.
I would lie awake wondering if it could be possible that I hit someone in the car on way home. Totally without sense but made no difference to the woosh of fear and adrenaline.
Would see a belt and have images of hangings.
Be driving and have the image of swerving to hit a pedestrian.
I had no wish to do any of these things at all. Only that I might have done them and somehow forgotten /would do them. I couldn't understand why I was thinking these thoughts, it's hideous.
At different points in my life the thoughts have centered around different things. I think if you don't understand what they are or indeed what they are not it escalates until you are on hyper alert against your own mind and you are stuck in a loop.
Mine would be worse in periods of stress or anxiety, worse when tired etc.
Seems to be the result of being someone very hazard aware that takes their own thoughts too seriously and is not comfortable with risks/ uncertainty.
Please do read the book, the way to deal with the thoughts is actually very simple and I have gone from being a quivering hyper anxious person to being back to enjoying life and rolling my eyes in amusement if a thought does ever pop up.
I really feel for you and am sending you much support and reassurance that all will be well.