"The Disease and The Cure" by Ibn Qayyim al-Jawziyah is widely available in PDF format online. However, I would recommend checking reputable sources, such as:
: The core disease of the human heart is sin, heedlessness (ghaflah), and corrupted desires . These lead to anxiety, depression, spiritual emptiness, and estrangement from God. Ibn al-Qayyim argues that every moral failing or psychological distress is rooted in a diseased heart. ibn qayyim the disease and the cure pdf
Five notable “diseases” and Ibn Qayyim’s remedies (compact two-column list) "The Disease and The Cure" by Ibn Qayyim