他因为单相思而整日郁郁寡欢，朋友们都很担心他的状态。

His friends worried about him as he suffered from ___love-sickness after his unrequited affection.

她的相思病表现为失眠和整天盯着手机等他的消息。

Her ___love-sickness showed as sleepless nights and constantly checking her phone for his messages.