I have repeated episodes of hypoglycemia. with good diet how long till they disappear ? can the episodes disappear completely?

Depends: If you have hypoglycemia while fasting, that is very concerning for an insulinoma. If you have hypoglycemia after eating and have been diagnosed with reactive hypoglycemia, the treatment is small frequent meals with minimal carbohydrates. Insulinomas require surgery for cure. Reactive hypoglycemia should resolve with the prescribed diet, but typically returns if you deviate from the diet.