How do you overcome lack of self-confidence?
Self confidence comes with competence in some chosen field or subject area, and this is amplified when applied in the service of others (meaning when you are value to others in some real way).
What are you good at?
May be you are a nurse, a teacher, an accountant or a doctor. Whatever you are, look at who you help and what impact you have on others.
Knowing that will start making you feel good about yourself (dont compare yourself with others though - that’s a mistake).
And finally, GIVE. Your time, resources or even a bag of meal next time you shop at the grocery store.
It will build a sense of confidence and self-esteem, you can’t miss it.