What is your opinion on my condition, which has been deteriorating for 4 years, and does what the Quranic healer told me—that what I am suffering from is a touch (of jinn) — necessitate treatment?

The ظاهر of the question indicates that the questioner is suffering from magic or the evil eye. The cure for this is reliance on Allah, frequent prayer, supplication, remembrance of Allah, lawful ruqyah, repentance, and seeking forgiveness. One must be wary of healers who ask for the mother's name and the mother's mother's name, or for something that belonged to the patient, such as hair or clothes. These are charlatans whom it is not permissible to approach or seek help from, for the Messenger of Allah, peace and blessings be upon him, said: "Do not go to soothsayers" and "Whoever goes to a diviner and asks him about anything, his prayer will not be accepted for forty nights."