久病成医孤久成疾
[jiŭ bìng chéng yī gū jiŭ chéng jí]
Derived from an ancient saying in China, 'become the doctor after being ill for long' which means gaining expertise from experience. But this netizen adds another level with 'long-standing loneliness turning into sickness', expressing a melancholic feeling towards chronic loneliness that turns into a mental health concern over time.