Glad that you have a doctor and physio you feel are doing a good job for you. It's important to have trust in the people treating you.

Its so important to try all the various pain management options. For me, my lumbar sympathetic block was diagnostic only - I had no pain relief and after the local anaesthetic wore off the nerve pain was even worse for a while but at least it confirmed the diagnosis. It was a fascinating procedure to watch as it was being done. I did get a very nice printout of my spine and the whopping great needle in my back from the fluoroscopy machine as a souvenir! TENS didn't work for me either - any electrical intervention made my pain much worse but it really helps some people. At least it is cheap, easy and non invasive so if it helps its very good news. It's also encouraging that your doctor has you actively working on the physio - more and more of the latest research work is supporting the hypothesis that intensive physio, in spite of the pain and lack of popularity with patients, is actually the way to go.

Fingers crossed for you.