Hair loss...please help peoples.?

iam 18 years old girl from pakistan.my hairs are weak and a bit thin and semi curly but i have no problem with that but due to some hair loss my Coiffure is become very wide from back of my head and it is as wide that i can see the scalp.iam very upset and sad i want to know does my hairs will come back and the area from which i loss hair will recover with new hairs?will my hairs regrow at that place? if yes then how long will it take to regrowth..and should i leave it to time to recover?