What Causes Dizziness After Stopping Zoloft?

I was taking 50 mg. of Zoloft for about 2 years. I felt well so my doctor suggested to decrease dose to 25 mg and stop taking them. Recently is my 5 day off Zoloft. I feel dizzy so I have to stay home. I am wondering how long that last or should I come back on Zoloft again. Thank you.