What is the diagnosis and treatment for severe fear of death and related obsessions that have caused physical and psychological symptoms, and is there hope for complete recovery?

It is recommended to ease the burden on oneself and avoid anxiety and stress after sincere repentance, for Allah's forgiveness is immense, no matter how great the sin. Allah Almighty says: "Say, 'O My servants who have transgressed against themselves [by sinning], do not despair of the mercy of Allah. Indeed, Allah forgives all sins. Indeed, it is He who is the Forgiving, the Merciful.'" [Az-Zumar: 53]. One must have a good opinion of Allah, for Allah accepts repentance from His servants. The state the questioner is in might be a trick from Satan to make her despair of Allah's mercy. She should resort to supplication (Du'a), for He, glorified be He, removes affliction. Allah Almighty says: "Is not He who responds to the distressed one when he calls upon Him and removes evil?" [An-Naml: 62].