Hi I Have Been On Seroquel For Just Over A

Hi I have been on seroquel for just over a year and the maximum dose I was taking 100 mg. It was them reduced to 50 and then 25. I eventually reduced the dose to 12.5 mg. I took 12.5 mg for a about 5 weeks and stopped taking the medication. It has been about 6 days since and I am experiencing headaches fatigue and stomach pane. Is this the usually withdraw symptoms and how long will they last for?