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 more photos of your head, by direct online consultation for accurate diagnosis and proper treatment.

Oil n shampoo has no role in preventing hairfall or growing new hairs....it seems u r suffering from telogen effluvium would request u to opt for online consultation as to understand the root cause n treatment.