I thought it couldn't get worse.

Last night my legs from the knees down felt like they were standing dangerously close to to a camp fire. My entire body was having horrendous shooting pains and twitching throughout. I actually felt like muscles and joints are being eaten and my insides were trembling.
Can anyone tell me what happens next? I have read about the burning since I was diagnosed with SFN, but this was the first time it happened.
I almost went to the ER.