I'm sorry to hear that you've been experiencing severe acidity for several days and have had ongoing issues for the past three years. Persistent acidity can be uncomfortable and may indicate an underlying condition that needs proper evaluation.

Here are some steps you can take:

• Dietary changes: Avoid spicy, oily, and fried foods common in Indian cuisine that can worsen acidity. Limit intake of caffeine, carbonated drinks, and acidic foods like citrus fruits. Incorporate millets, dals, and vegetables which are gentle on the stomach.
• Meal habits: Eat smaller, frequent meals rather than large heavy meals. Avoid lying down immediately after eating.
• Lifestyle: Maintain a healthy weight, avoid smoking and alcohol, and manage stress through relaxation techniques.
• Medications: Over-the-counter antacids may provide temporary relief, but since your symptoms are chronic and severe, it is important not to self-medicate without guidance.

Given the duration and severity of your symptoms, I strongly recommend consulting a gastroenterologist. They can perform appropriate investigations to identify the cause and prescribe suitable treatment, which may include medications like proton pump inhibitors or H2 blockers.

If you experience alarming symptoms such as difficulty swallowing, persistent vomiting, weight loss, or black stools, seek immediate medical attention.

Taking these steps and consulting a specialist will help manage your acidity effectively and improve your quality of life.To narrow down potential causes, we will need some more information.Please tell me your age and gender.