梦已醒你已走心已凉
[mèng yĭ xĭng nĭ yĭ zŏu xīn yĭ liáng]
'Dream has woken, you've left, heart feels cold' paints a vivid picture of post-breakup grief or melancholy after waking up from a beautiful dream to stark reality, implying deep sadness and loneliness after separation.