Fell on my back 3 months ago?

I fell on my back about 3 months ago... Everyday I have sharp shooting pain in my upper back. I went to the doctor and with out any xrays she said it was the muscles and sent me to physical therapy for that.... But I am responding terribly to the PT everything he has tried puts me in a tremendous amount of pain.... he doesn't think it is the muscles as Im not responding to ultra-sound, massage, strength exersise,or changing my posture.... Should I get a differant doctors oppinion??