the key to developing self esteem is self-compassion. if you’re too hard on yourself and refuse to forgive yourself for small mistakes then you’ll never feel comfortable as yourself. to become a person with self-esteem you have to learn to love yourself and hold yourself in high regard. that means stopping negative self-talk, treating yourself with the same kindness you’d treat a friend with, and forgiving yourself when you mess up.
once you learn to treat yourself with kindness the rest falls into place, bc a lot of that lack of self esteem is practicing being overly critical of yourself so you’ve gotta stop doing that x3

sorry if this isn’t that helpful but i’d search online for things like how to practice self-compassion, loving kindness, things like this. i heard this from my therapist in my own work on my own self esteem so hopefully it can help you too!