Upvote:4
You will not be 'sent back', but the chances are that the airline won't ever let you board to begin with, and your ticket is lost (=no money back).
You will need to show the airline proof of your citizenship, in a way that is defined in TIMATIC (the database airlines use for that).
The easiest way is surely to apply for your Italian passport right away at the next embassy, and then travel with it.