there are a few diff reasons of why this may of happened. one you could be allergic (if so im so sorry). two it could of just been 2 strong for your second time. 3 you could of just smoked too much for your tolerance. 4 it very well could be all in your head (i know it sounds wierd but its true). i recommend gettin some low potency shwagg/commercial and only taking one hit out of a pipe. wait a couple minutes and see how you feel. one you get a small buzz stop smoking. repeat this and slowly start smoking more. I had this same thing happen to me when i first started smoking. now i can smoke with the best of them lol. (well from where im from anyways. our weed sucks!)