What Causes Neck, Eye And Head Pain?

Hi, I have pain in my neck(left side),left eye, left eyer and left side of head. All these I feel are controlled by single nurve. this problem i am facing since 6 months. I feel some extra part is there in my throught. I am a regular drinker and i smoke 5 to 6 cigatette(Since 5 years). I had habbit of chewing tobbacco. I have quit all these since 2 months. Am I having a risk of cancer.Please help me.