I find some long term strategies help - routine, exercise, getting enough sleep, managing your stress in a healthy way. When all of these things are in check I have fewer full blown attacks and recover faster. You have to be strict with yourself on these things- you NEED them rather than WANT them, they are necessary.

In the moment- I try to remember to breathe deeply and slowly into my belly, hold it, release. Usually in a panic attack you hyperventilate which makes everything worse. I also often will do some sort of calming gesture like stroking my arm and tell myself over and over in my head 'it's okay, you're okay, you're okay, this is going to pass.' If I'm in the midst of being overwhelmed I try to choose one thing I have to do (the first thing) and tell myself that's all I have to worry about right now. Congratulate yourself after every thing you do. I have found panic attacks, while still definitely unpleasant, are not as terrifying as they were at the outset. Because I know I've survived them before and I will again. You will too.

I know because I've been there that you may well read this, and go yeah, that all makes sense, but this is intense and horrible and I feel like I'm going to die and/or lose my mind and how will breathing exercises and getting enough sleep really help? They are sort of pat, common sense replies, but taken consistently over time they do really help, they reduce attacks and make you healthier and stronger and better able to deal with the ones that still come. You will survive. You will.