Hi fiftygirl,
Sorry to hear you are feeling like this.
Keep in mind panic attacks are very scary and a lot of things go on in our mind that makes them worse. It is easy to say but don't feed the panic attack, when it happens let it go, concentrate on your breathing and try to get it regular, take a deep breath in, count till 5 and let it out slowly thinking "relax". Have a paper bag handy if you hyperventilate. Distract your mind to let it pass. Look at a picture or something and start analysing every detail, ask yourself what color/shape/weight it is, look around you and try to find small details in things, distract your mind and tell yourself, this is just a panic attack, it can't hurt me or kill me, it is chemistry in my body, I can do it.
Hope you get the appointment soon to treat your anxiety. Are you on hrt at the moment?