I can’t figure out which one it was but
https://www.mangago.me/read-manga/geu_kkeute_issneun_geos/
https://www.mangago.me/read-manga/a_shoulder_to_cry_on/
I also remembered this while looking. Can’t remember how big of enemies they were because I read it 10 years ago but I KNOW the love interest is MY enemy (hate him)
https://www.mangago.me/read-manga/never_understand/
I HIGHLY RECOMMEND THIS!!! i‘ve read a lot with the same trope before, but this is the best for me. i haven‘t read anything as good as this and im not even kidding THIS IS WHAT ENEMIES-TO-LOVERS SHOULD BE LIKE
https://www.mangago.me/read-manga/olgami/

i NEEDDDDD smthing abt 2 ppl who are extreme extrem extremeeeee enemies, like despise eachother. with massive amount of tension. im not talking abt petty rivarly typpa stuff