爱你如病已入膏肓
[ài nĭ rú bìng yĭ rù gāo huāng]
'Loving you as an illness in terminal stage'. A hyperbole showing unconditional love towards another person or thing. 'Disease in terminal stage' implies an overwhelming obsession beyond control or cure. This expresses deep love in rather sadomasochistic and self-destructive manner.