Have a read of the comments above where there are over 800 experiences of withdrawing from Effexor. I am slowly weaning off. Before I went cold turkey, and was fine after 2 weeks, but had to go on to it again. This time, with my doctor's help, I am withdrawing from 150mg daily over a year, as I am told, the slower the better.
Hope you feel better soon. I am told what you are feeling could be withdrawal. When I stopped before I was well for a year, and then had what I thought was depression returning. I am now told it could have been withdrawals, even after all that time. this time I will ride it out for longer. I don't know how we can tell which is withdrawal symptoms and which is the return of depression. Seems they both feel the same.
I've been on Effexor for 5 years and turns out I stopped it because of the physical harm it does to the body (especially the heart) and then I felt like you felt-all over the place and incredibly depressed. I then went on Zoloft which 9 months later doesn't work now! The Effexor worked for me but I can tell u, I really found it v v hard to get off of and I was on half the normal dose. Good luck with it. Maybe there's something you our take to help like diazepam to help you get off the withdrawal symptoms?
I've never taken Effexor, but I read your post and I wanted to let you know that I've went through similar feeling after stopping other medications. I don't know, maybe your doctor will want to try a different medication, or a smaller dosage of Effexor. I hope you feel better soon.