Having a panic attack while super high is awful. It's like a regular panic attack, but the sense of dread and lack of control over your thoughts is amped way up. At least that's how it was for me the few times it happened. It's part of the reason I try never to get too baked. I'm good with a single 5mg edible every once and a while. My days of bong rips and blunt rotations are behind me