The information you gave is inadequate to properly treat the condition.We need to know whether there was a antecedent acute illness like typhoid or dengue which might have precipitated a condition, called "telogen effluvium".
Sudden changes in diet,fluctuations in weight,scalp infections could also be the possible causes
Next Steps
Relax and consult a dermatologist/aesthetic physician to have a proper assessment and treatment
Health Tips
You can consult me on practo direct for more information