Xanax is the best solution I have found for acute attack management - that is unless you want to spend months/years in cognitive behavioral therapy which isn?t a bad option if you have good health care.
Other things that help are knowing the following:
It is impossible to faint if you are laying flat on the ground or with your legs elevated above your head. So if you feel like you are going to pass out (common panic symptom) lay down and elevate your legs.
There are Millions of people around the world who suffer from the same thing. You can find a whole lot of them online any hour of the day and just connecting with others helps a lot.
It WILL pass. I know in the heat of the massive surge of panic that doesn?t seem the case, however knowing that will help. Also if you need a "safe way out" keep a cell phone in your hand. If you DO need it - know that it is there and the medics are only a call away.
Cold water works miracles. I don?t know why or how, but cold water on the head or face, or even slamming an ice cold glass of water seems to distract your body from whatever physical symptoms you are focusing on to another area of focus.
Breathing exercises are helpful, as many people mentioned, however without proper training often they aren?t very useful. Best advice with breathing (if you feel you are choking) is to try to slow everything down and focus only on the breathing alone. If you feel your throat is closing drink some ice cold water and you will realize that your throat is just fine - if it can swallow it can breathe. NOTE: Often many of the feelings are caused by a REAL affect of panic which is hyperventilation. Realize however that this is NOT fatal, and if you lie down flat and put your feet up there is no way it can harm you.
Time is also on your side. Panic attacks are awful however they will pass and if you can find a way to simply distract yourself... TV, GFY, Cleaning, fleshlight (Thanks Juicy). Basically anything that can shift your focus away from the panic - even slightly can assist until the feelings subside.
Finally and IMO most importantly talk to someone you trust during the attack. Describe your symptoms (that helps diffuse their power) and keep them on the phone or in you presence for as long as you are suffering the effects. This helps tremendously as if you are really going to die, they will be there to assist but most realistically they will help distract you, calm you and diffuse the power of the attack until it passes.
Also it sounds like you are beating yourself up about the condition - that is almost as useful as yelling at your body because you have cancer. Anxiety disorder is a BIOLOGICAL condition. There is nothing you did to cause it and nothing you can do to cure it. That said understand that it?s NOT fatal nor is it untreatable. Contact a good healthcare provider well versed in the disorder and begin a feasible pathway to coping. You will never be rid of it - however you can and will be able to live with it.
Sorry for the ramble. I have dealt with this shit for years so I wanted to pass on what I have learned.
Good Luck!