I'm sorry you're experiencing this. I can speak from my own experience and knowing that you also have SFN. SFN can and does cause tremors/vibration/shaking. In my case, it's a prominent symptoms. There are times that my entire body shakes, though more often it's my left side and lower in the body. I have lots of muscle twitches as well, including complete spasms or jerks of parts of my body when trying to sleep. Finally, I have very prominent tremors/shaking in both my hands. I should also say that I often get dizzy when I stand, because of my dysautonomia that comes along with SFN too.

I wanted to add that there is no evidence of motor involvement in my case. All tests have been negative, and I seem to only have small fiber involvement.