This sounds a lot like what I had. I was sick for a week! And it was so weird, because all I could really describe it as was that I needed to lie down all the time - and sleep most of the time. I had occasional chills/sweats. I also had a very noticable decreased appetite.
I did call my doctor and they recommended rest and fluids. I went to my primary on day 6 and they gave me a zpack - she said that far into it my body was having trouble fighting it off and needed help. Right on cue I started feeling better again the next night. I wasn't back to "normal" though until day 11.