Yes! Same drug too. I was on Effexor for a couple years. It didn't really do any good for me. They kept raising the dosage and it still never really made me feel noticeably better. I got the same dizziness when I'd forget to take them for even a day. The second day would be really bad...and I can't even imagine going 3 days. The "brain shivers", as you call them, seemed to happen when I turned my head, or even just my eyes. I also felt like I'd get a little bit of this withdrawal every day at a certain time...like it was wearing off...but my doctors said it couldn't wear off. Of course, they also told me that you don't get withdrawal from it.
Since it wasn't doing me any good, I decided to get off it. It SUCKED. My doctor gave me prescriptions for 1/2 of what I was taking, then 1/4, then I took half a pill (1/8), ....but every time I actually tried to really stop, I'd get the dizziness back. I ended up breaking open the pills and just taking some of the little beads whenever I started getting dizzy. STILL, even after being down to that small amount, it sucked when I actually did stop. I felt like s**t...and I had to do it at work. I will never go back on that crap.
However, if it is HELPING you when you are on it, maybe it's not really that bad for you. If you're getting headaches and stuff like I did, I'd consider a different drug, but if it's helping you, it's up to you whether the withdrawal symptoms are worth it.