By reputation, Prozac and Lexapro have the least side effects. That doesn't mean much for you, though, as has already been stated, and it doesn't mean they'll work, either. Often, the better a med works, that means it's been metabolized better, and thus, alas, the more side effects. Clonazepam, by the way, is for long term use, not necessarily short term. Xanax or Ativan would be more likely to be given for short term use.
I'm still new to this medication stuff. If it was working for you, why did you go off of it. Is that what you're suppose to do with antidepressants?
The thing is all AD are affect people differently. About 6 years ago I started on Paxil for anxiety/panic. Probably only made it a couple weeks. Then i tried Zoloft and it worked for me...this was about 5 years ago so I really don't remember how I felt when i started (i was pretty low at the time so it all blended) but I just started on Zoloft again last week and the first 5 days were tough. Today is day six and I think (hope) I am through the worst of it (although I still have a headache). I have was on Zoloft for 2 1/2 year and off it for 3 years. My point is the start up is always tough. You just have to find one that works for you. Keep in mind that you will get better.