Answer
(Fatwa: 184/184/L=1431)
In spite of being married, you mentioned yourself as unmarried in application, so it was a lie. And when you make a duplicate Nikah Nama of current date, it would be another lie. However, if, out of helplessness, you do not find any solution, then you can adopt this method: Give your wife one talaq-e-bayin and perform your Nikah within iddah period after getting permission in the presence of legal witnesses, and then you can get the Nikah Nama accordingly with current date. But, in future you will own only the right of two talaq-e-bayin. This can be done with the help of any Aalim.
Allah (Subhana Wa Ta’ala) knows Best
Darul Ifta,
Darul Uloom Deoband