Sinking too deep in your rabbit hole, now I'm drowning in love is a Manga/Manhwa/Manhua in english language, ROMANCE series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.cc fastest updating comic site. The Summary is

Due to a painful heartbreak, Kirino decided to give up on love and instead obsess over her favorite anime characters. One day, a transfer student named Kametani shows up, and he acts and looks exactly like her favorite character! On Kametani's first day, he tells all the girls, "stay away and don't talk to me." Despite his intimidating aura, Kirino tries to get closer to him, and she even uncovers a surprising secret about his past...