JazakAllah Khair for sharing this, Tahurra. InshaAllah I will watch it over the weekend. Ibn Qayyim also has a really nice book on Diseases of the heart; I have not read it yet but inshaAllah hope to. It can be obtained as pdf from kalamullah.com among other works from various scholars; May Allah forgive them all and bless them for their service to Islam.
Walaikumussalam Warahamtullah
Yes the biggest disease of heart is qaswatul quloob (hard heart) may Allah protect us Ameen..
Ameen at dua and may Allah forgie us too Ameen
So is one whose breast Allah has expanded to [accept] Islam and he is upon a light from his Lord [like one whose heart rejects it]? Then woe to those whose hearts are hardened against the remembrance of Allah. Those are in manifest error. (22)surah az zumr