Any manwha/mangas that delve into the topic of loneliness?

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

Also manga like,
Three days of happiness
Oyasumi punpun
My broken mariko
Shimanami tasogare, fit the category too I think

Baraou_no_souretsu
Deep blue child

One of the most heartbreaking realistic and sweet stories ever https://www.mangago.zone/read-manga/can_t_see_can_t_hear_but_love/