Well, you already know this by experience, but Effexor is one of the most difficult meds out there to stop taking. Because you weren't on it all that long, hopefully you'll be okay, but nobody can tell you how long the window is because it varies much more than you think -- some people have no problems, most have moderate problems, some have long-term problems. Which is why you can still go back on it and taper off slowly if it doesn't stop soon -- that option isn't gone.