The same thing happened to me on Paxil. I tried it for a couple of weeks, but the effects were too much - I felt like a zombie, so the doctor switched me to Effexor, and that was a lot better.

If you're really concerned you should go back to your doctor and discuss all this. There are a lot of options as far as anti-depressants go and sometimes it's just a matter of finding the right one for you.