伤心伤肺如今我已百毒不侵
[shāng xīn shāng fèi rú jīn wŏ yĭ băi dú bù qīn]
It means 'Heart-broken so deeply as if lungs also hurt, but now nothing hurts me anymore'. It shows having endured tremendous pain (literally 'hurts heart hurts lungs') from past, but such experiences have made oneself numb or untouchable by sadness eventually - no more vulnerable to emotional damages after all those suffered.