Open Question: I have a question about marijuana?

So, I used to smoke all the time. I stopped 2 years ago though. Is it normal to feel like you're going to die [at the time I had been smoking about 2 years and never experienced it before]? My heart was racing extra fast and beating hard [ I could feel it]. I seemed out of breath. I was sweating, and my head was pounding. I had a huge headache. My stomach was hurting. I laid down for 2 hours straight and it was still happening. I know being paranoid is normal, but I also thought someone was trying to kill me. I did not feel safe outside my with friends. It's not like I smoked a lot. Two of my friends and I shared one blunt. I also puked. I smoked WAY more than that and never had a problem until then. Is that normal? Could it had been laced with something? I want to know so I can get more educated on drugs and what they do. Thank You.