Dr said ok to stop xanax (alprazolam) after 2 wks. of .5 or 1.0 every couple days. 3 days after stop feel little weak, shaky, some nausea, anxious, flushed. if too short a time for withdrawal, why feeling this?

It's withdrawal : Most likely based on your history. Xanax (alprazolam) or Alprazolam is very potent and physical dependence (causing your symptoms) can happen very quickly, a matter of days possibly. It affects everyone differently, some become dependent more quickly or slowly than others. You should talk with your primary care doc or psychiatrist (the one who wrote your prescription). By the way, you are not "addicted.".

Anxiety symptoms: These are symptoms of anxiety or they could be symptoms of an underlying medical conditions causing your anxiety in the first place. Please return to your family doctor for evaluation. If you need further help then you can discuss with your physician other options for treatment of anxiety including psychotherapy, antidepressants for anxiety, yoga, biofeedback, neurofeedback , and acupuncture.