brain fog caused by rear end collision?

I was rear ended November 13th, 2010 and I thought I just had whiplash, and minor back problems from it. Well the last 2 months or so, I have been having this feeling in my head like I'm just foggy all the time, so that is where the brain fog comes into place I believe. I can't concentrate, I space out easily, all I want to do is sleep. I like naps occasionally, but everyday it seems like I wake up and I just want to go back to bed 30mins later, I have no motivation for anything. I've been eating healthier and it still continues to be a problem. I'm miserable over this because I don't feel normal...My head doesn't feel right. So I guess I'm wondering could I have like a brain injury or something that was caused by my accident???

I know I sound like a crazy person here, but I am going crazy over feeling this way. I just want to feel normal again.