How to tell a freind why you cried in class?

my really mean teacher insulted me and my project. while the quiet class in front of me and her was all staring i was thinking of saying something back but that always makes me cry... well that happaned i walked out of the class and she chased me. there is probley rumors going around and freinds going why you cry? but i have no exuse i cannot controll my tears that well but what am i suppose to put in this rumor and tell my freinds.