When I was a kid, there was a period during which I was convinced my dad was planning to kill me (or have me killed). I’d have regular nightmares about it.

I have one [non-dream] memory in particular where we were walking through Belfast on a sunny Sunday afternoon, it was pretty much empty except for us. We were walking along a path holding hands (I was like 6 or 7), and an alleyway opened to the right of me, and I thought “this is it…” and was expecting a masked gunman to come out, and for my dad to let go of my hand and step aside, his job now complete. Genuinely thought that was about to happen and almost had a panic attack. No idea why I thought that, or why I eventually stopped thinking it.

I was later diagnosed with all sorts of neuro/psych shenanigans, so I guess it was probably that. I still have intrusive thoughts, but I’ve had therapy so I’m a bit better able to manage them. CBT might do you some good if you have access to a shrink. You can even do most of it on your own, or with a bit of guidance from someone else who’s already done it.