Re: vitamin D deficiency. does that explain my symptoms?
18 is very low for vitamin D and it does take awhile to raise the level. Your rheumy is right about taking D with a meal including fat. I would also suggest taking K-2 as well as it helps the D go where it's supposed to go.
My only other advice would be to take a calcium supplement other than carbonate, which is probably the least desirable form of calcium. Some of your symptoms may be due to the side-effects of this supplement. I like Ezorb but there are other good choices as well.