PLEASE HELP! Xanax vs. vistaril?

I have been taking .5 mgs of xanax for years with no ptroblems. However. I would like to change to something called klonopin as sometimes have amnesia on the xanax. My dr. wants to give me vistaril, which to me sounds like an enhanced version of benadryl, which I already take. By the way, the reason for the medication is I have crippling anxiety attacks to the point of not leaving home. Can someone PLEASE explain the difference between vistaril and klonopin? You may be saving my sanity. Thank you so much.