It's very typical to get a reoccurence of the original symptoms after stopping these kinds of meds (sometimes worse than the original symptoms), so my guess would be possibly rebound anxiety/depression. You should be well past the acute withdrawal period by now.
My advice to you would be to talk with your doctor about this. You have a few options. You could give this some time to see how you feel a few months down the road, you could try to restart the Effexor, or try a totally different medication. Sometimes the "adjustment" periods after d/c'ing these meds can last a lot longer than you would think, and everyone is different.
I have seen so many people decide to stop taking a medication because they felt they didn't "need" it anymore, only to suffer with a reemergence of the intial symptoms, because the medication was actually doing a lot more for the person than they realized. I've done the exact same thing, on a few occasions. You just may end up needing something more long term, and if that ends up being the decision you and your doc come to, that's OKAY. There is nothing wrong with that. NONE of us really WANT to need a medication, but some of us do, plain and simple.
I hope you are feeling better soon. Please update us, let us know how you're feeling!
It has been 3 months since you quit taking it completely. I found when I quit this med it took a very long time to get over the withdrawal. It's really hard to say if this is what's going on with you. I do know that some people experience anxiety and depression after quitting these meds. I really wish I could be of more help to you. When I quit taking it I started another med right away which helped my anxiety and depression. I'm not saying that's what you should do. It really could be withdrawals, and or rebound anxiety and depression.