I have had MS for years now, diagnosed officially for 4. I also have bouts of
the full body "achiness", its very uncomfortable and painful. My last bout of
it was last October, it felt like I had the flu and ached in every joint, muscle
there was, only my head was normal. Went to the doc and he prescribed
"baclofen" and it helped immensly. I don't like to take drugs unless I
absolutely have to but at this point (after a couple of weeks) I took them. It
eased up a couple of weeks later after I weaned myself off the pills was the
only way I could tell. Go see the doctor and tell him about it, baclofen is
used for all sorts of things other than MS pain, but it certainly helped me.

Hope this helps :)