I know how it feels to have a panic attack and it sucks sooo bad. A little over 20 years ago when I was 18 I got some super stinky roadkill skunk smelling weed, so strong it made your nose burn a little just smelling the bag
. Anyway I hit it just like I had always smoked and about 5 min later I was in a full blown panic attack, thought I couldn't breath, that my heart was going to stop, pretty much thought I was going to die. If I remember right that went on for about 30 mins to an hour before I finally started hyperventilating and passed out lol. Needless to say I quit smoking after that for a long long time, really just started back up about 4 years ago. I was always afraid that it was going to happen again.
So long story short is just to find the strains that work for you, and always be careful with new ones if your still worried about anxiety/panic attacks, and as the song goes "Take it Easy"