How To Overcome The Withdrawal Symptoms Of Zotral?

Dear Doctor, i have been on Zotral (Sertraline) for almost 3 years. I have tried to stop intake from time to time as for once i don't intend to0 continue for ever & it is expensive. However, every time i try to stop, i get a burst of confidence for about 24hrs & them go back to my depressive moods. Even more than i started. Pls let me know if i will ever be able to stop intake. My dosage is 100 mg.