I've had two panic attacks to date from smoking..
one happened when I was in a car and hadn't smoked in a while..after smoking I felt an urge to get up and pace...and a feeling like I couldn't breathe..
Another time we all smoked an excessive amount of bong rips and we were playing mario party in a dark room with the sound too loud..again I felt as if my lungs were failing and I had to stand up quickly and breathe heavily and slowly to make the feeling subside..
I was going to say your stuff was laced but chances are it wasn't..
take it easy..ease into it if you continue..don't bomb yourself