S.G.
I get that also but I usually can do stretches and it usually helps. I think it is in the muscles or back out of line, especially since you said your back was hurting this makes sense.
The head scan might be a good idea. It could show if you have a blockage or anurisum (Sp?) or even the beginning of a stroke. If you were just forgetting things like someone's name it wouldn't be bad but getting oppisites mixed up is more then just memory loss. It could very well be a life saving scan.