As another responder also did, I went off my 150mg VERY slowly. Took me months of splitting doses, then almost counting the little white balls in the capsule. I still had symptoms, but nothing like some people get with flu-like symptoms.
After that, I had the occasional mild depression, but nothing I couldn't live with. But after 9 months, both the depression and anxiety started getting bad again, and after another 3 months I went back on... only to have it be less effective. All that to say that everyone is different. Heck, I'm the same person and it is working different for me than it did when I first went on.
I'd certainly not go off cold-turkey. You really can't go off too slowly. But if after that, if you are still haunted by the monster, sounds like you need Effexor or some other anti-depressant. But I'm no doctor.