I woke up with a tremor in my right arm. It's been two months and both my arms, legs, and head all have a subtle tremor. My head does a constant bob up and down. I have tingling and burning sensations all throughout my body, mostly in my legs. My muscles twitch randomly in different places, and I sometimes have pain that is unprovoked, mostly in my wrists and upper back. I've had numerous blood test done and a normal MRI of the brain w/ and w/o contrast. Please tell me what this is likely to be?