[Lumos.]

I've had that problem a couple times when i had a panic attack. The best advice I have is distract yourself. Keep your hands busy as Julia said. Remember to keep breathing, and distract yourself.
Here's the alternatives sticky, there are quite a few good ones that have distracted me in the past.

Is there anyone who you trust and can call when you are having a panic attack? Someone who will just talk with you until the urge subsides maybe. Or maybe if this happens again call a hotline, they can help calm you down, and can really help.

I know its hard to control yourself when you have a panic attack, but i know you can do this. Stay strong.
Hope this helped.