I'm no expert but to me it sounds more like a neck issue than reagravating a concussion (don't know if that's important to you but I know that for me it helps my anxiety tremendously if I think it's neck related rather than causing more damage to your brain). Maybe try and relax and treat your neck and I'd say don't stress over this too much.

For me personally I try to take a wider perspective on my symptoms and how I'm feeling so instead of monitoring myself day to day(which fluctuates a lot), I compare myself to how I was doing say 2weeks or a month ago. If I'm at the very least not worse than I was a month ago I know that im probably going in the right direction. I probably have something at least 10 times per day that Im pretty sure wouldn't damage my brain (stepping too hard, bumby metro, stressful event) but causes my symptoms to flare up even just momentarily. If I stopped every time something like this happened I'd never make it through the day.

Don't really know where I'm going here but try not to label what happened and just treat the symptoms and I'm sure you'll get back to normal soon. And if you really wanna label it I'd personally say it was just irratating your neck a bit rather then your brain.