While it doesn't go into much depth of the actual day-to-day conditions in Italy after the First World War, u/Klesk_vs_Xaero offers an overview of the country's unstable internal political situation in this answer, which might interest you.

But the answer is still important, as the rise of Mussolini was begotten of political maneuvering as much as it was a product of a social movement. More on the "Social Movement" and its staunchest (and most violent) activists can be read in this other answer by the same author.

As I have tagged them in the answer, u/Klesk_vs_Xaero might also comment in their own right and offer additional information or links to additional answers which I haven't read.

I myself have done some reading on the topic and wrote this answer which is very aligned to your question topic a long while ago, which might interest you. However, I am not as well-versed in the topic u/Klesk_vs_Xaero (my answer was written before they were an active user) and they might be able to point you to a more complete answer.