Most of the time we lack self-esteem simply because we don’t have a positive opinion about ourselves. Do you stand in front of the mirror and actually feel good and approve of what you see? ( I often do not!)
If we feel good about ourselves that means we develop confidence which boosts our self-esteem. They go hand in hand. You have the freedom to think anything you want. So why not create the habit to accept yourself for who you are with love and appreciation?