When I came off fluoxetine I did so complete cold turkey (I'd had a manic episode which ended with me completely florid, and trying to kill myself). I had these weird electric shock sensations in my head. Took quite a while for them to subside. After that I was off meds for a while, then the doctor put me on something else (can't remember what now). It just made me tired, to the point where I would just sit for hours on end staring at a wall unless someone shook me out of it. When I came off that med, I started getting the electric shocks in my head again. I spoke to the doctor about it, and he said it shouldn't be happening, but that sometimes a person's brain became used to detoxing in a certain way, so I was having "phantom withdrawal" from whatever the med was... in other words my brain learned to zap shock me when I was coming of a drug.

Since then it's happened again when I stopped a drug... perhaps this is what's happening with you?