Lithium "withdrawal"?

I recently stopped taking my lithium for bi-polar disorder. My doctor said it was ok to stop taking it because he placed me on a new medicine so that I wouldn't relapse into a manic episode. I have however, been suffering from some symptoms since I quit taking it a couple of days ago. I have experienced headaches, nausea, dizziness and hot flashes. I was wondering if anyone else had had these symptoms before, or any others when they discontinued using their lithium?