I don't get them from pot but I do get them driving. Bumper to bumper at 80mph, Califonia drivers are either the best or worst, still not sure yet.

Anyhow, I just tell myself "hey, this is just a panic attack, nothing to worry about, just calm down" Acknowledging the panic attack for what it is always helps. Then have something to drink and just take some nice deep breaths. It should pass.