No ability to concentrate while medicated

Unmedicated I can't concentrate because I'm having chest-crushing anxiety and my thoughts flutter.
Medicated (Xanax 0.25, now Klonopin 0.5mg) I have some relief from the crushing feeling, but cannot concentrate because my brain is fuzzy or I am tired. When I say that I can't concentrate, I mean I can't read and recall anything, write proper sentences without a lot of thought, etc. My job requires that I understand and synthesize lots of written material, so neither the anxiety nor the fuzzy-headedness works for me.

I'm meeting with my psychiatrist soon to discuss the effectiveness of my medications, but I am curious as to how common the whole see-sawing between extreme anxiety and extreme zonk-edness is; whether that's more likely to indicate the addition of something to fight side effects or if it's possible to use benzodiazepines without losing all ability to function.

Any thoughts on my Klonopin woes?
Many thanks!