If your anxiety is this severe, you probably need to seek professional assistance as soon as possible. Anxiety is one of those symptoms that exacerbates the more you think about it. Xanax should be helping with this, but if not, you need to seek help for the immediate problem symptom.
Since you are also experiencing a poor appetite and poor sleep, it is becoming a physiological problem as well. I am not sure if you are describing olfactory hallucinations with the sense of smell but it is worth checking out.
Phone your MD or go to the emergency room for assistance. They may want to admit you for a day or two and assist you in getting the physiological needs met by getting a stronger medication for sleeping and the anxiety.
As you probably know, anxiety is also a symptom of depression and could be causing the other problems as well.
Please let me know if you have other questions. Gina