You are misunderstanding the instructions. They want you to take one every night before bed, please check to make sure that is what the pharmacist wrote on the bottle, if not then check with the doc in person, it could be a communication error.
Then if you are having a anxiety/panic attack, out in public and life suddenly goes wacko then take one. That is what it means to take one when you are having a severe one. You are actually having one that is out of control and not able to stop, relax, breathe, and re-focus your mind to something not related to agoraphobia. I had the same issues when I had panic attacks. I would totally freak if I were trapped at a stop light or in a seating situation. I had to be where I could make a right turn on red in traffic and in a meeting I had to be right by the door. If not I would just sit and keep looking at the door and in my mind I would be imaging I would fall down and make an idiot of my self if I needed to escape so the actual content of the meeting was lost on me. At church I would sit in the foyer if the back seats were taken.
These are called avoidance behaviors and I do them so well. I used to do them, it doesn't bother me much anymore. I worked hard and flooded myself until it was not an issue anymore.
Therapy can really help you learn good relaxation and how to stop, recognize where the panic is coming from (the trigger) and stopping them from happening any more. It may take years to finally see the end of them but it is do-able.
Knowledge is wonderful and I can promise you that once you see what the trigger is it won't have this power over you anymore.
My triggers were being out in the wilderness away from medical care therefore I could not leave home without my safe person... agoraphobia, my dad died in the Arbuckle Wilderness.
Then I could not do traffic where I was trapped and could not get out...claustrophobia, probably from where we had an accident in Norman and a semi ran over our car during a wreck and that really tore me up mentally, duh, we were sitting 3rd in the row at a stop light.
Being alone especially without the ability to contact a person to talk to was a wild one, I had to be able to talk to a person one on one right away so I would know I was not alone.
Find your triggers and they lose power, you gain control. Then no more meds.
You need to sleep very well. Your mind and body will repair itself much quicker if you are rested.