Headache after hard sparring - exhaustion or concussion?

[mozilla2004]

I should also mention between Round 1 and Round 10, I have a few sips of water. I think I only drink about 150 ml during that time. But I make sure i drink a lot of water when im finished sparring.

And also, I'm 5'8" tall and weight 158 lb. My opponent is 6'0" and weighs 180 lb. If i were to evaluate my opponent's punching power, I'd compare it to some strong amateur 130 lb guys I've sparred in the past. My opponent is still new, but if I'm not careful, his punches can stun me.