Italian Citizenship

Hello Guys
I have a very important question.
I was born in italy but my parents are not form italy.
They are from africa.
They tried to apply for my citizenship when i was born but they said i was too young.
Now i'm 19 years old and i live in the united states.
I'm wondering how will i be able to get my citizenship now considering i no longer live in italy?
I need to know what to do.
I want to be able to go back the place i grew up freely.
It's my hometown!!!!!
Do i need to go back to italy and spend some time there before i get my citizenship?
I have a italian birth certificate to prove i was born there.
I need help!!
Any Advice?
Thanks