First of don't stress since that may exasperate the problem. Second before you can start to cure it you need to identify the cause. Have you recently moved to a new city? Change in diet or stress levels? Are you having corresponding problems like acne? Is the hair loss rapid or gradual? Once you can narrow down your symptoms it will be easier to identify the solutions. For example, high stress can cause hair loss. Similarly, rapid hair loss or hair loss in combination with other symptoms can be hormonal and would require you to consult a doctor. In the mean time you should start taking vitamins like biotin and make sure you are eating adequate protein. Also, change your shampoo to ones with less harsh chemicals. If your hair falls the most while washing then cleanse only using a conditioner or apply an oil, like coconut, almond or argan oil, 10-20 mins before wash since that increases the elasticity of your hair.