What is something that I can remember while having a panic attack that can help me calm down?

You can remind yourself that it's not really happening, that you're not really in danger, and that you're okay. Just find a mantra that works for you. I find that just chanting the same thing over again can be helpful.

First of all, remember 4-7-8 breathing. Inhale for the count of 4, hold for 7, and exhale through your mouth for 8. Repeat 4 times. It will help you calm down by breathig deeply and by bringing your attention to your breathing, not symptoms. Also try to make tiny pieces of paper with writings like "I've been through this not even once and I survived, so I will this time too" or "This is just temporary, it will pass, it cannot carm me". Keep them in your wallet or near to you, you can put it to little box, and hide in pocket. Whenever you have panic attack, read it and keep repeating it in your mind or out loud if you can. That is what I do, and it helps me a lot.

Remember the last time you were truly happy. Place that makes you calm. Song that you love. Try to find good things, count them all and breathe.

First and foremost, know that it will pass. Concentrate on your breathing. (You can practice slow and deep breathing in and out when you're not having a panic attack, so it becomes second nature to you.) You can also talk to yourself, like a friend, and walk yourself through it. For example: "You're having a panic attack. It's ok. You will be ok. This will pass. Just breath, deep and slow. Very good. Don't worry, I am here for you. You're doing an amazing job. I know this is hard, but you will get through it. You always do." It works for me. I hope it will help you.

To count down from 10 to 1 slowly. This psychological trick will trick your brain into focusing on the logical task of counting rather than the panic. Also helps to get out of bed in the morning ;)

Focus on the moment! Start listing things around you in the present second that you can experience with your five senses, this should distract you from your thoughts that brought on the attack.

this will pass. you have had them before, and you have gotten through this before. breathe. make sure you breathe, and focus on just your breath for a bit. now look around. what are some things you can see? can you name five? what are some things you can feel? your clothes against you, your hands touching something, your feet on the floor? concentrate on what you can feel. can you name four things? now what can you hear? cars outside, a fan, random tapping sounds or buzzing? can you name three? can you smell anything? the scent of a carpet, or pencils, or clean linen? if you can't smell anything, what are some things that have strong scents? imagine it as vividly as you can. think of two things. and lastly, what is something you can taste? does your mouth still taste like toothpaste? like your last meal? if you can't taste anything, what is something that you really like to eat? what does it taste like? name one thing. now, back to your breath. breathe in and out, slowly, gently, and focus on how your chest rises and falls. you'll get through this. you'll be okay.

First of all, remember 4-7-8 breathing. Inhale for the count of 4, hold for 7, and exhale through your mouth for 8. Repeat 4 times. It will help you calm down by breathig deeply and by bringing your attention to your breathing, not symptoms. Also try to make tiny pieces of paper with writings like "I've been through this not even once and I survived, so I will this time too" or "This is just temporary, it will pass, it cannot carm me". Keep them in your wallet or near to you, you can put it to little box, and hide in pocket. Whenever you have panic attack, read it and keep repeating it in your mind or out loud if you can. That is what I do, and it helps me a lot.