any genre is fine :3

Possibly The Makeup Remover
Odd Girls Out
maybe Bless?
Jibun Size de Ikou Watashi nari no Body Positive
I found this mangalist that I think fits the criteria you are looking for: https://www.mangago.zone/home/mangalist/487147/?filter=&page=1

Enjoy!!

Tysm !!

https://www.mangago.zone/read-manga/kasane/

Thanks !

Insecure about his masculine body
https://www.mangago.zone/read-manga/home_ep/

Insecure about his height
https://www.mangago.zone/read-manga/two_size_two_small/

Insecure because he looks like a tough guy but he's actually a big softie
https://www.mangago.zone/read-manga/the_first_love_of_the_sushi_restaurant_owner_is_a_mermaid/

Insecure about his facial expression
https://www.mangago.zone/read-manga/one_side_in_room/

Everyone's scared of him because he's so big
https://www.mangago.zone/read-manga/bongchon_bride/

Thinks he's unworthy of affection
https://www.mangago.zone/read-manga/doppleganger/

Has a scar on his face
https://www.mangago.zone/read-manga/falling_star/

Insecure about his small body frame
https://www.mangago.zone/read-manga/app/

Insecure about his weight
https://www.mangago.zone/read-manga/my_pudgy_co_worker_is_a_snack/

Insecure about his gender identity
https://www.mangago.zone/read-manga/shucchou_host_nyu_boy/

Insecure about his weight
https://www.mangago.zone/read-manga/bro_do_you_think_i_m_fat/

Wow tysm!