hello dear , I have been in same situation it is not possible to get married until you got all the proper documents they ask for .
you need birth certificate , register of civil status (to proof that you are not married ) with apostilles , proof of incomes from you and your fiance , passport copy or original .
I don't know where you come from but I have made an authorization to a Notar and sent to my mother so she was able without me going in my home country to take all those documents .In other case I would suggest you to find out if there is any Consulate of your country in Italy so maybe they can help you .
wish you good luck