This isn’t strictly a resource but I would create a list of things that you want to do- Like learn a new skill, get more fit, change your die and then create a schedule around it. If you spend your free time locked in to doing things that bring you joy and improve your life you’ll become more confident and won’t have time to worry about self esteem
using your resources such as hobbies or whatever outlet you might have for mindfulness like meditation, singing, gym/exercise, for some people it can be religion. I’d say a key part is acceptance of who you are and if you’re not happy about it then plan a course of action that you’ll stick to improve yourself
The Quran and Al Ghazali’s revival of the religious sciences books. It’s more about de-centering the self, centering God, and finding self love via recognizing God’s love coursing through every aspect reality. Like yeah I’m not perfect and I’ve got my own issues, we all do, but we have purpose and are loved. I know not everyone’s religious or muslim, but that’s what rly helped me personally. Basically I found self love through loving God and other people first