I've been taking Zoloft for about 3 years now. I haven't been taking it regularly for a year or so now, and I haven't taken it in a week. I have gone longer without taking it before, but this time stopping I am noticing some syptoms. I cannot sleep, feel as if I cannot breathe/tighness in my chest, light headed , tingling in my hands. I get it sometimes in really bad spells, and the doctors don't know what it is. Could this possibly be Zoloft withdrawal?