Hello all. I'm new here. Not sure where to post this, but it seems relevant enough.
Let me start with what I believe was my first concussion. A couple years ago I was working out with one of those rubber tubes with handles at the ends. I would attach a caribeaner to the center and,say, a chain link fence.
Well, all I had was a gate. Long story short, the caribeaner slipped off the gate as I outstretched my arms and hit me square in the back of the head. My ear rang and I saw silver streaks in my vision but that was about all.
Flash forward to a few weeks ago, a coworker jokingly tried to slam a door on my arm... Only he hit my head. I didn't experience any symptoms (that I know of), but ever since then I've been experiencing crippling anxiety of whether it was a concussion. Reading articles about permanent damage from only one or two hits was enough to scare me big time, especially since I'm about to start college. I do score very poorly on online memory tests, but I don't know if it was caused by that door hit or if I've always been that way. Mostly I'm afraid of living a normal life.

What do you guys think? Am I paranoid? Could I really have a concussion without any symptoms?
Thanks in advance