I'm sorry that we cannot actually write your letter for you on here. However, I think I can give you some ideas about what you might write.
First of all, I think you should write about how Mussolini's government is improving the way that things in Italy are being run. Things used to be all inefficient and corrupt. But under Mussolini, things are being run much more effectively. As they say, at least the trains run on time.
Second, I would emphasize how the fascists are keeping people like labor unions and socialists and communists under control. This makes things way better for people like you.
Finally, you could say that Mussolini is going to get Italy back to being respected in the world.