Using a throwaway due to subject matter, but I also learned the hard way that cannabis just doesn't agree with me the way it did in my younger years. I had what I now know to be panic attacks a few times after smoking a bit of weed and it's not worth the risk for me anymore. It's a bummer because I used to occasionally smoke when I was in my 20s with no issue other than maybe feeling a bit groggy in the morning but now it's a tossup whether it will mellow me out or leave me a wreck off a few puffs.
Had a couple of panic attacks unrelated to any sort of mind-altering drug as well and I actually did drive myself to the ER because I didn't know what was going on. I thought I was having a heart attack or a stroke or something (which of course doesn't help the panic attack). Heart wouldn't stop racing, blood pressure through the roof, dizzy, trouble speaking, etc.
I kept the rest of the handful of Xanax I was prescribed in case I have another one someday. No desire to pick up a benzo habit but the few times I thought I felt something similar coming on in subsequent years, half a tablet (whether through placebo or drug effectiveness) made it fizzle out before ramping up into a full panic attack.
It's weird because I had thought knowing it's a panic attack and not a heart attack/stroke/whatever would "disarm" the process but it doesn't seem to matter. Still interested in figuring out what can cause that to happen seemingly out of nowhere.
Feels like a feedback loop where normally mild anxiety comes and goes in the course of daily life but in rare cases, instead of "turning the mic off" it stays on and the feedback builds to a point that is overwhelming.