I have been taking Geodon for three years (ever since it came out...

I have been taking Geodon for three years (ever since it came out in February 2001). Originally at 160mg/day I am now at 80mg/day taken at night. It doesn't make me sleepy and never has, however I notice if I forget to take my Geodon at night I wake up with a terrible headache. I know then that I have forgotten to take it, take some and the headache disappears. I believe there is some withdrawal associated with it. The only other side effect I have noticed is the restlessness, constantly fidgiting.