I am sorry to hear that you are suffering so much. You appear to be in the first stage of complex regional pain syndrome (CRPS). In this stage there is intense burning pain. This is followed by stage 2 and 3 wherein skin changes and muscle wasting etc sets in. Usually this stage is manageable by steroids, pain killers, spinal cord stimulators, intrathecal drug pumps etc. A very important component of treatment is occupational and physical therapy. This along with cognitive behavior therapy teaches you ways to manage this pain.
Along with this, cool moist drapes over the affected areas help bring temporary relief to burning. High dose steroids are often very helpful in controlling the inflammation and thus reducing the pain. Vitamin D you are already taking. Along with this vitamin B12 supplementation may also help. Please try physical therapy and cool moist drapes until you cans see your doctor. Take care!
The medical advice given should not be considered a substitute for medical care provided by a doctor who can examine you. The advice may not be completely correct for you as the doctor cannot examine you and does not know your complete medical history. Hence this reply to your post should only be considered as a guiding line and you must consult your doctor at the earliest for your medical problem.