Last night, on a section in the back of my head, I felt some sensitivity and pain. There was a small lump I hadn't noticed before as well. I felt a little "off" all day, lightheaded and almost weightless. A few times things like patterns felt like the were moving, and moving my head too quickly made me dizzy. The pain is still there today, just not as severe as it felt last night. I did get hit snowboarding by someone coming down the mountain in that exact spot on my head, by I was wearing my helmet and it was a week ago. Wouldn't I have felt all this before if it was from that? What else could it be?