Stop it. There are many reasons for hairfall or thinning of hair on the scalp. So first and foremost we have to find the cause with the help of detailed history and examination. Some of the common causes are nutritional deficiency, hormonal causes like androgenic alopecia or patterned baldness, hypothyroidism, telogen effluvium etc. Unless we find and treat the cause there is no point in giving non specific treatment. Oils or shampoos do not have any effect on hair growth as they are not absorbed in the skin. Moreover, you should never self treat with anything. Please call me or send photographs using online consult option for proper diagnosis and detailed prescription.

At your age it can be nutritional if periods regular

No.. Specific medicine required...You are suffering from hormonal changes causing Androgenetic alopecia causing hair fall. It's completely stoppable even regrowth of hair is possible with certain medications without any side effects. Treatment depends on the grade of hair loss. So, it's a must for diagnosing which grade, you are in for an effective treatment. Please  send photos of your head, by direct online consultation for accurate diagnosis and proper treatment.

Ideally we have to go for investigation to rule out underlying deficiency, thyroid disorder etc.. if it is male pattern baldness, folliserum is adjuvant. Mainstay is minoxidil