Hello, Welcome to health care magic. Severe hair loss over few months to years is called telogen effluvium. It is a hair loss pattern usually triggered by a physical illness (like viral fever, typhoid fever, hepatitis, etc), stress, crash dieting, weight loss, child birth and surgery which you would have about 3 - 6 months prior to onset of hair fall. It could also be due to underlying anaemia and thyroid abnormalities. You need to check your hemoglobin levels, serum ferritin levels and thyroid status. You could benefit from taking oral supplements containing 5 mg biotin once a day fro 3-4 months. Have a good diet rich in protein. For dandruff, wash your hair with an anti dandruff shampoo containing ketoconazole 2% and ZPTO 1% thrice a week. It is better to avoid oil. Hope this helps you. Take care.