Since your panic attacks are happening less, are the headaches numerous and a reason that you cannot take the
medication anymore? Or are some of the
side effects okay with you now that your anxiety is much better?
What does your prescribing doctor say about this? Headaches can also be caused by an endless number of factors in my opinon. Are you getting enough sleep? Are you still under a lot of stress? The point is, that the headaches may not even be related to the medication itself.