Many times it is just how you get hit not how hard....Remember Naseem Hamed he knocked guys out with the most unorthodox punches you ever seen..Angles are a great weapon....if you think you are suspect in an area just work on covering up in that area more....From what you say though you just had a guy who took liberties when he shouldnt have knowing your experience level...If it is any consolation you were hit in the temple not the jaw and anyone I mean ANYONE can go down from a shot to the temple....
As for the worrys of being in front of a crowd and getting KO'd...Thats a normal feeling any new fighter has...I suggest working out in front of as many people as you can while sparring to get past the crowd shyness...HEY REMEMBER everyone has been KO"D in front of a crowd....Even Ray Robinson, Tyson, Lewis, Hearns ect....just part of the game