Selling is really acting.
When you get up in the morning, whatever suit of clothes you put on, that's your a-game uniform and then it's show time or it's time to play the game.
It doesn't matter who you naturally are. Leave that person at home because that person probably is not what you need to be in order to make money. You've got to step into the role to be something different than who you are. Because not too many people want to do business with you the real you.