So sorry to hear you are feeling worse instead of better. I recommend calling your doctor's office tomorrow. At least talk to the assistant or nursing and ask about your reaction. The sympathetic nerve ganglion are right on top of the motor/sensory nerve they feed into. On the spasms and pain my guess would be the area either got "buzzed" so to speak by the injection or there is some swelling in there in reaction to the injection or possibly because of displacement from the injection depending on how much volume was used.

If you end up with no relief it seems fair to ask if the doc thinks this means you don't have sympathetic pain or did they not quite hit the spot? Did your limb warm? That might give a clue if placement was good....

Hope you feel better soon,
Littlepaw