Is it possible that the symptoms the questioner is experiencing are a response from Allah to his supplication, in that He deludes him with illness so that he may become regular in prayer, and how can he rid himself of this delusion if that is the case?

The Prophet, may Allah bless him and grant him peace, forbade a person from supplicating against himself, his family, or his wealth, lest it coincide with a time when supplications are answered. Therefore, your supplication against yourself to be afflicted with calamity goes against the prophetic command, and that might be the reason for what has befallen you regarding neglecting prayer and studying. You must increase your supplications for Allah to grant you well-being, take measures to ward off illness, and make up for the missed prayers.