Panic is wasted energy, so don't stress about that, just deal with the new symptoms as needed. It doesn't really matter if a new concussion or a re aggravated one.
Same result, increase in symptoms..
Do you have a knot or bump from hitting your head? You can Ice that to reduce any swelling..

Rest the brain as much as you can, eat healthy , get plenty of sleep plenty of fluids, and quiet time. Avoid junk foods ...