After a panic attack? How many days will. I feel. Okay again? How many days will I be exhausted?

Hard to say. The best predictor of future panic attacks is the frequency and duration of prior attacks. If you have them infrequently, you may not have another for weeks or months. Many people have several a week for long periods. Therapy and medication can be very effective treatment for panic disorder. Good luck!
Panic attacks. It's hard to answer your question without knowing whether you're receiving treatment for your panic attacks. If you are, you need to tell your doctor so that medications can be adjusted or changed. You should not be feeling exhausted for days after a panic attack. If not in treatment, please see your doctor for eval and meds. These work together with psychotherapy, which will also benefit you.