You had a panic attack. I suffer from the same thing. I believe that I am currently going through withdrawal after I quit smoking weed a month ago. I smoked a lot. Different people have different bodily reactions, and handle THC in a variety if ways. I quit because it got to the point over last Christmas Break, leading up to 2014, my chest would hurt really really bad, just about every time I smoked, and it would get so bad I'd swear I was having a heart attack. But no. I'm only 16. That can't be possible, and was proven after I saw a doctor (who didn't know it was the weed causing it) who told me my heart was fine. After I quit (around January 5th) I started suffering from anxiety even when I was sober. I'm still suffering from chest pain, dizziness, numbess, tingling, and feeling of impending doom. I suggest quit right now, cause you seem to be having the same reactions as me, and I don't want you to go through what I'm going through. Quit! So you don't develop an anxiety disorder. Hopefully these symptoms will end eventually (which will prove to me this is withdrawal from Marijuana). If not, this means weed caused anxiety problems, which I hope isn't the same case for you. If so, see a doctor! It is in no way harmful or life-threatening, but is a pain to live with, and very scary.