Chronic Pain In Lower Jaw. Painful To Eat, Difficulty Brushing Teeth And Drinking Cold Drinks. What May It Be?

Hi My name I Graeme Wilce I live in Christchurch New Zealand. I think that I may have T.N. on my left lower jaw, I keep getting this chronic jabbing, stabbing , electric shock like pain,in my left lower jaw line, its not from my teeth , I checked with my Dentist ,and its not T.M.J. It is painful to eat most of the time,and its hard to brush my left lower back teeth,and drinking cold drinks, A-N-D even my saliver can bring on this excruciating pain..can You Doctor XXXXXX say what it may be??? This afternoon I have an appointment with my Doctor as well 20/12/2012 Thank you very much .