If your user name appeared to be a real first and last name (fictitious or not), your user name has been changed to just your first name. As of May 1, 2018 no full real names are allowed as user names.
While you sometimes feel good about yourself, you tend to struggle a little with self esteem issues.
It's not about changing who you are, it's about accepting your faults. You just need to be less critical and demanding of yourself!