Panic attacks maybe? But choking... that's not good. Perhaps you should see a doctor and just get checked out, I honestly wouldn't suggest talking to him/her about the weed, because if you tell him/her "I choke everytime I smoke" he'll/she'll just say "dont smoke". Try their above meathods... smoke half of what you did. I find if I smoke too much at once, I throw up and get sick.

Just out of curiosity, do you smoke cigarettes? I've seen cigarettes do that to people when they smoke one before or after smoking weed.

Sorry if this didn't make sense.
I'm stoned.