It’s been almost 2 month since i had HPPD, I am not sure I am having HPPD or not. I had only a half of single stamp( lsd), first time experience, I never used any hallucinogenic drugs before except some weed . During the trip I smoked some weed too.Initial few hours were so euphoric then something went wrong I wasn’t feel happy. I called my buddy. And he was high on weed, when I was at peek he tried to scared me. I really scared. I can’t say it was a bad trip. Later the comedown, I was normal. After that day onwards I am having severe anxiety and panic attacks.after a week panic attack has gon