What Causes Pain In Face,jaw And Behind Ear After Total Thyroidectomy?

I had total thyroidectomy due to cancer. I also had a golf ball sized tumor schwannoma removed from my neck at the same time. It s been over 4 months and I still hurt all along my left side of face, jaw and behind my ear where tumor had grown. This pain is such that it almost brings me to tears when I shave. How long should I allow for healing before I make an appointment with a neurologist to see if something can be done.