Sorry, I'm prefer manga>webtoon but here are some I like (some might not be toxic enough):
https://www.mangago.me/read-manga/camellia_minami/
https://www.mangago.me/read-manga/youkoso_new_world/
https://www.mangago.me/read-manga/public_sex/
https://www.mangago.me/read-manga/nani_mo_iwanai/
https://www.mangago.me/read-manga/fruit_of_the_tongue/
https://www.mangago.me/read-manga/the_prefect_s_private_garden_8232/
https://www.mangago.me/read-manga/deichuu_no_hasu/
https://www.mangago.me/read-manga/dear_crazy_monster/
Anything toxic tbh, doesnt matter if the relationship gets healthier or not. Can be sl, bl, or gl, and i would prefer something with colors please (if its a rly g black and white one then I dont mind)