Thank you for your question. Islam is God centric and so the self esteem the human has is the honour that God has endowed him/her with in choosing him as the best of His creation. Self worth comes from being honoured in front of God and as God says in the Qur’an, the most honoured in front of Him is the one who has the most taqwa (God-consciousness). This view of the value of humans has a number of implications:
1) It clarifies the boundary between arrogance and self esteem. It is a realistic picture of the human as a servant of God that gives him honour, not an inflated opinion of himself that he imagines to be his value. His worth is not based on whether he considers himself better than others. Rather, his worth lies in his relationship with God.
2) It induces hope. With the door of repentance always open and a relationship with the Generous, the Kind and the Merciful there is never any reason to feel down. God has ordered us to have a good opinion of Him and blamed us if we loose hope in Him.
3) It clarifies the boundary between humility and abasement. Humility is God centric and is with God and for God amongst His creation. Abasement is between humans due to their selfish desires and does not take away from the honour of one who rises above it
Increasing self esteem is to increase your faith, love and trust in God and the Infallibles (as). It is to educate ourselves in understanding our role in this world, increase our servitude and to be more humble in front of God. There in lies the true value of every human and with it their understanding of that value which is their self esteem.
May Allah grant you success on the path of His Friends (as)