I think it’s a Japanese or Korean movie I saw, in the crime / drama / murder genres. If I remember correctly, the main character is a doctor at a clinic and lives above a butcher shop. And kills people through a sleep deprived split personality. At one point he finds body parts in his fridge and tries to hide it from his ex who occasionally visits or something. I believe he is also friends with the detective that’s hunting him. I might be mixing up two movies lol. Does this sound familiar?