Abilify will generally be beneficial for anxiety, though it can also be a side effect. This is common for anti-anxiety medications, that occasionally they have increased anxiety as a side effect. Xanax has the potential complication of being short-acting, causing anxiety quickly as it wears off. It is also difficult to be taken off of it, with a withdrawal syndrome being common. I would consider going with your provider's recommendation if you trust him, or getting a second opinion. If you try the Abilify, and it happens to cause anxiety, then your provider might switch medications. Good luck!
-Eliot Seigle MD