Oh! And i thought about this one ,
https://www.mangago.zone/read-manga/hidamari_ga_kikoeru/ (he's deaf and his self esteem took a blow coz he became a bit of an outcast coz he can't hear what his peers are saying at school :-o but then comes our happy-go-lucky MC who is so loud and so clumsy too! :-) and he instantly feel better :-)! (But still a bit unsecure so this story fits !)
This manga also is super interesting https://www.mangago.zone/read-manga/double_noda_ayako/
mc feels insecure about his intelligence and his ability to provide for the ml basically (its a bit deeper than that but yeah) https://www.mangago.zone/read-manga/sangyang_the_wanderer/
I would like to read about characters who feel ugly or unloveable in some way. Or characters with low self esteem.
Any gender and any genre. Thank you so much! (●'◡'●)ノ