I feel soo depressed ?? !!!!!!!!!!!!1?

i m doing my engineering (b-tech 1st year) and i don't know wat's wrong wid my lecturer. he's always verry serious and scolds everyone without any reason. but for the first time he called me and beat me hard only because of some silly reason and that too in front of everyone. the reason was that nobody were sitting in the bench which was in front of me and he asked me y didn't i sit in that bench so said a bit loudly that "sir i thought someone would come and sit here" so he called me and beat me soooo hard in front of everyyone and said that i should learn manners and i should know how to behave and talk properly with lectures. i felt sooooooo embarrased and humiliated. wat to do i m sooo deppressed about it and i don't want to attend his cles now. he scolds without any reason. i wonder how should i behave with him??????????/