The method to overcome this feeling

The method to overcome this feeling is by going through the source of our problem, changing the negative image of our ourselves, changing the bad impression of ourselves and finally by telling ourselves that we are not that vicious and that we still have some virtues, then smile at yourself.
To blame, reprimand, condemn or punish yourself will make you feel depressed and sad, then you cannot smile or if you can it will be a sad smile.
Whenever you have to greet someone, just keep on smiling.