Hoarse voice since childhood

I am 22 years old. I have hoarse voice something similar to teenage boys..
I have visited many ENT specialist for the concern.. Every time they say there is allergy in my throat and nothing else and gave me medical prescription.
But nothing went good for me. I every time feels hoarseness in my voice.
I am very disappointed for my future concern. Every time doctor say allergy but it never been treated which affect my voice.
How to solve this problem???