Thank you, Bud. I agree with you, that sounds very unlikely. I wish I had videotaped my sleep to know what exactly happened
Perhaps I woke up but fell asleep soon again, and do not remember that. Or perhaps the hit was strong enough to cause a brief loss of consciousness. Or perhaps the hit wasn't that hard, and it is just a subconcussive impact which is causing all these symptoms now. I am speculating, as I have no idea at all - the only tangible piece of information is the physical bump and the sudden return of all symptoms after that night.
Anyway, I'll follow the usual advice from this site now - rest, go back to some non-stress activities quite soon, and try to keep my mind busy.
Many thaksn again for your patient advice and help.