What Is The Cause Of Numbness Of Thumb And Painful Neck?

I am having terrible pain right where the neck meets the back and slightly below. Pain radiates into my pectorals (if women have them) and sometimes my left arm feels weird. My left thumb gets numb as well. I noticed when I get my hair washed, it is hard for me to hold my head (seated at the sink in the salon) steady. Last week, I heard a draining noise in the back of my head and suddenly my ears felt clear. I can't sleep a night without constantly shifting positions. What is wrong with me?