I just think that any bump to the head with an elbow like I got is a concussion.

When I got that blow/bump, my head moved to the right (the elbow came from the left and moved my head to the right) but I didn't feel strong jarring. I mean, I didn't feel the head shake but the impact still made it move to the right when it happened. Isn't any bump that causes the head to move quickly to one side count as a concussion, or a sub-concussive impact?

I had a small return of symptoms after this, but this might have been because of my intense anxiety.

So how do you think that this bump will affect my recovery quality/length? Also, you said you have gotten 14 concussions, most of them mild to very mild. When you say very mild, do you mean bumps like that or something more powerful?