Fell down, not feeling so good

I fell on the ice about an hour ago. I fell right on my knee which is cut up pretty badly and very swollen and bruised.
The fall hurt WAY more than I was expecting it to. It had this deep pain that really caught me off guard.
For some reason, I'm really paranoid now. I'm not feeling well all of the sudden (kind of nauseas), and I'm wondering if it's all in my head? Or if a fall on my knee could actually cause enough damage to make me sick...?
I think I've been watching too much Grey's Anatomy. Every fall turns out to be a crazy, ridiculous injury that would have killed the person. I want to keep myself safe, but I also want to not be crazy.