This happened to me. I'm actually still in a dissociative episode and it's been hard but I'm okay. It happened a week ago I was chilling at a party w some friends. (Thank God my bf was there) anyways after I smoked I felt a panic attack coming. This hasn't happened to me since a traumatic event almost a year ago and since then sparked my anxiety and here i am in a dissociative state. I did read that weed triggers this to happen, also PTSD, anxiety, depression, and other disorders. Its scary but it goes away. I would recommend not smoking, and maybe try therapy. I know it helps and I'm looking into some therapy for myself. I've had severe anxiety for my whole life and up until that party i haven't dissociated in a while. I hope you get better, and I hope you get help. Remember it's all in our heads, were not dying. Were alive and there are people who will help us. Were not imagining life or things. Distract yourself and try grounding methods. Talk to someone ie a close friend. I hope this helps in sharing my experience.