What Causes Severe Pain In Arm And Neck?

I seen my doc 1st week this month cause my left arm, neck, hand is aching(pain) and numbess& tenging in and my left upper chest off and pain, my doc said i had a pulled muscle and nerve running from my neck down my arm and hand, he gave me something like prednisone it was a 6 day pack then i called him the 7th day, told him i was still having the same promblem and he called in another one and last friday i went to a walk in ER and they said i had hypokalemia and cervical myelopathy and needed a MRI and make a appointment with my doc. i have crohns & colitis, arthritis, high blood presser, half of my left kidney, fibrolmyolgie, and migraines, some other small thing, but i m not a big water drinker either, my body smell like vingare and is dry, why i m still having problem .