I'm very glad you posted this. Knowing someone else is experiencing the same thing as me is heartening.

I feel this, what you've described, almost every day. In situations where I'm at all close to hitting my head, I'll develop uncertainty as to whether or not it actually did occur - when in reality, it very much did not.

I can't offer advice at this point, as I'm still struggling thoroughly with this issue. Really, I've just been to occupied with other things to make a thread about it.

I just want you to know - you've described it well, and I'm right there with you. I struggle with imagined head hits almost every day.