i have been in a lot of competitions. well, to be honest, i have lost more than i have won. but i am not depressed. neither do i feel useless. winning n losing is just a part of the game. u can't be the best all the time but u can be at your best anytime u want. it's quite difficult to make people understand that losing to a better person or team is absolutely fine.
when u lose, don't lose the lesson. find the ways to improve. and life goes on. u'll be happy always without losing the hunger for success. just give ur best for every game and be satisfied! winning alone isn't everything!! :D