Today I sat in my school regularly in my class at a break and some of my friends were standing and talking behind me.

One of them suddenly accidentally hit me in the head with his elbow when he was talking to his friends (he tried to explain to them something with his hands and hit me in the head by accident).

This is my third concussion and I'm really afraid it'll worsen my injury significantly and prolong my recovery time. These things are, sadly, sometimes unavoidable (what could have I done to avoid this concussion?)

I try to avoid it as much as I can, but this today has already happened. Even though he hit me in the head by accident (he was not running or something, he stood still when it happened) I think it was still strong enough to cause a concussion (a direct blow to the head from my friend's elbow that he moved when he spoke with his hands - I was just too unfortunate that he was behind me when he did that). He didn't move his elbow too quickly but it still hit me.

What should I do right now? Rest? Try to avoid additional blows in another way? Take supplements ASAP to reduce further damage?

Thanks,
-ProAgonist