Hi there --
While the presentation is really pretty strange, I think deeper consideration should be given to neurological causes, especially now that the discomfort has spread and symptoms have evolved. One thing that may not have been considered is a variant presentation of MS, which can cause these sorts of painful body "hugs." These are spasms that usually show up later in the course of this particular disease, but MS is one of those oddball diseases that can show up in a number of disguises. It's just one possibility, but I feel it hasn't been ruled out at all, so should be at this point. There are still other neuro possibilities, but I believe in getting the big things out of the way first. An MRI of the brain wouldn't be out of order at this point, and while that's needed usually for a ruleout of MS, it can also expose other things that could be causing this. The muscle fatigue and cramping and fatigue, along with rather random pains and stiffness do sound suspiciously like an MS-related problem. It could be totally off base, but it's suggestive enough to rule this out. If that's done successfully then there's less urgency to sort out the rest of this, and those exams, as with the MRI, could expose some other potential causes as well.
Hope this helps. Good luck to you and please follow up with us as needed.
John Kenyon, EMT, CCT
Non-invasive cardiology tech, Emergency and Critical Care technician, Critical Incident Stress Mgmt. specialist