Minimac, you're most definitely allowing your anxiety/obsession to take hold, and I'm confident that this worrying poses a far greater risk to your health than anything that you have done with your head as of late. Trust me; I've been trying to get over the very same mental obstacle for the past year, and I'm still not quite there yet.

For example, a part of me still thinks that I'm experiencing concussion symptoms as a result of a particularly "vigorous" activity from earlier this week... I don't quite know how to say it on this forum, but yeah. Sure, it caused my head to jerk around a bit, and—even despite the fact that I've had far too many alcohol-related concussions within a very short timespan (recently, too)—I have to keep telling myself that I'm fine.

As of this past pseudo-incident, hitting the books intensely for a few hours will cause me to feel a pressure sensation in my head, but I'm able to make it disappear instantly by simply relaxing my cranio-facial muscles. Now and then I'll notice what seems to be tinnitus—no, now and then I'll resolutely convince myself that I'm experiencing this hallmark symptom of concussion, but then I tell myself that I've always heard this noise, that even my healthy brain had regularly perceived this kind of sound.

You'll be fine. People keep on learnin', world keeps on turnin'. You're ten years post-concussion, and you've only had one...I remember hitting my head pretty hard only 10 or so months after my initial concussion as a kid, and I was fine. In fact, before my more recent "set" of alcohol-related concussions, I busted up my teeth (and my face) on some ice without cognitive deficit.

Persistence is great in the pursuit of knowledge, and I'd encourage you to go explore the scientific literature ad nauseam (if that's your thing), but obsession and incessant self-projection will eat you alive.

Cheers!