Weird day

So, I woke up this morning feeling great. I got in bed at about 8:30 last night, and actually went to sleep at 11. My neck was KILLING me, so I spent a long time trying to get comfortable. My headache seems to be based in my neck. It's just so weird...I've never felt like this. So anyway, I woke up this morning feeling good. I was hoping that this was done. At about 1:30 this afternoon (right now, it's 3:00 Denver time), I started to feel weary and my neck started aching. Right now, I feel like I've got a head cold that's situated in my neck and base of my head. My reactions are delayed and I'm freezing. I felt like this last night too, and I took my temperature and was fine. But last night, the pain was more towards the top of my head and in my neck. I'm starting to get a little freaked out. I'm not sure what's going on. This morning I was fine, and now I don't even want to move, and I'm scared to drive home.