Withdrawal usually kicks in around 24-48hrs after stopping. If you stop Geodon abruptly, you can get quite severe (but quite rare) symptoms after 2-3 days - these include nausea, headaches, vomiting, rapid heart rate, insomnia and a few others. You can also experience feelings of restlessness and involuntary muscle movements. Sound familiar?
One of the major risks is a major relapse back to original (psychotic?) condition.
Go back to your doctor & suggest that you would like to come off Geodon over a 4 week period. Tell him/her that you are experiencing severe withdrawal symptoms and don't let him/her fob you off by saying 'these will pass'. You may have to be quite assertive with him/her to get what you want, but the withdrawal can be made easier to handle if your meds are slowly reduced. Do not do this by yourself.