It can be caused by many problems. It can be stress, genetic problem, health issues. If you have hair loss in so young age it's better to visit a specialist. I also have hair loss and use special shampoo, creams, eat more fruits and vitamins. I read that hooded hair dryers make like massage effect for head and because they make warm air for all hair, it stimulates better growing. I searched online and found good reviews, you can
read more. Also if someone can make you a head massage it also can help, even 10 minutes every day make you more relaxed.
Good luck!