I have had this issue before and it was low Vitamin D. I have reoccurring bouts with it and it often happens if I have a metabolic imbalance due to dietary issue. Perhaps asking for a Complete metabolic panel and a Vitamin D test might provide you with answers or at least a starting point to begin ruling out things. I was miserable as it literally felt like I was walking on broken bones daily.
SLE w/Sjogrens Overlap and Raynaud's diagnosed in 2007.Fibro in 2009.
The Early Bird May Get The Worm But the Second Mouse Gets The Cheese.