I Had An Almost Life Threatening Situation With Marijuana, Hear Me Out, What Could Have This Been?

I smoked some pot that I had just gotten, a bowl full. I went to my room and was on Facebook for a bit when my head started to feel like it was burning but it didn't hurt it was just uncomfortable and odd. I lied down on my bed hoping it would pass but then I felt something odd coming on, my entire body was engulfed in this feeling that I can't describe but I sort of thought I was about to have a seizure or something so I sat up super quick to snap myself out of it. I almost went to sleep but I didn't want to sleep yet, I wonder what would have happened if I did... I went to get some water and couldn't even really pick it up properly to drink it, my whole vision of things was lagged in that I would move but I wouldn't see it happen right away and I hardly felt it either. I stumbled, having a hard time walking, to my twin brother's room who had just smoked some of the same pot to ask him if it was making him feel weird. It wasn't, he was just good and baked. I felt really strange and looked super pale apparently so I went upstairs to show my parents what was going on. My pupils were FULLY dilated and non-responsive to changes in lighting, they would also roll up into my head sometimes, I was pale as a dead person and my brain was not functioning normally. My lips were colorless. We phoned an ambulance. I was also seeing geometric shapes over top of everything but sort of see-through and kaleidoscoping. I couldn't even verbally describe what was wrong with me, I couldn't compile the words into a coherent sentence aloud, but I was really scared, I ordered my family members to get me some paper and a pen so I could write down what I was feeling, for some reason that was easier. It genuinely felt like I was going to die. My mom who is a nurse was having a hard time finding my pulse. When the paramedics arrived they had the same issue, apparently my heart was functioning at about half of what it should, they didn't seem optimistic about my condition, they seemed surprised that I was conscious. I was seeing these odd almost ripples coming off of anything that moved. I just kept telling myself that everything would be alright, when the thought of death came on I said in my head NO NO NO NO NO NO NO NO NO again and again, I wasn't done with this world yet. I stayed in the hospital for a bit and even just sitting in the ER room bed my heart was beating abnormally fast, my mom and brother could see it beating from where they were standing, it was shaking my shirt. A few of the times when they took my blood pressure I could hardly even move my arm. I eventually, after a number of hours, calmed down to the point where I just felt out of it and tired like I still do and a doctor came to talk to me and ask me what happened. Her diagnosis was that I had gotten something or other dilated from the marijuana. I had smoked pot many times before this, I hadn't had any in 5 days for sake of cutting back and before I had been having like 3 bowls a day. This was not just marijuana but I have a hard time understanding what it was because it did not adversely affect my twin brother with the exact same DNA as me. It's my understanding that nobody has ever died from marijuana, and I could have. At the time, as weird as this sounds, I felt like I was awake and asleep at the same time, or somewhere in the middle, it felt like the essence of my being was almost trying to pull out of my body, as odd as that sounds. A cop confiscated the marijuana and as far as he could see just from looking at it, it wasn't laced. If it was laced with something, what could have it been? And why didn't it affect my brother, and if it wasn't laced, what the heck happened?