welcome to HCM
You are young and need to take care of your hairs
Normally also hair grow in cyclic pattern; scalp hairs rest for 3 months and it is normal to lose some hairs during this state.
is a conditional shedding of abnormally large quantity of hairs in situations like certain stresses such as pregnancy
, surgery, acute febrile illness, acute psychiatric illness or severe emotional or physical trauma.
Is there any fungal or other infection like dandruff
Loss of hairs at other part of body may also point out at endocrinal problem that is some hormone problem.
In the mean time keep your head clean,do some YOGA and Meditation
to keep stress to minimum.
It is good that you do not smoke or drink.
Consult a Dermatologist
who should help you certainly.