Been there, but it can be controlled. Most of mine turned out to be from lack of sleep due to Sleep Apnea which is pretty common. I was desperate. But the apnea treatment got rid of 90%, what's left is just from everyday stress. Might want to get a sleep study if you don't sleep well and jump up in bed in the middle of the night.
Prior to the treatment I used a lot of mental tricks and breathing exercises to calm it, with the occasional prescription Xanax. It helps to think of anxiety as a wave that comes and goes. As long as you ride it out, you'll be fine on the other side.
Helps to curl up under some warm covers too and try to sleep it off.
Also, if you think about the anxiety too much it creates more anxiety. This is due to re-experiencing prior episodes in your head. Try to just forget about it and the panic attacks tend to stay away. Most importantly always remember there is nothing wrong with you, you're basically hyperventilating with most attacks.
This isn't medical advise just my own recollections of my specific issue in the past, but maybe you can find something of help or support in it.
RE: A Prisoner Within Myself