I have done insurance claims many tines and strict policy wording exist for case like this. if your flight was not cancelled by CX (that is you got email saying you got cancelled) to start you have little to zero chance as what you have done is voluntary last minute change of travel. good luck

given sense of panic to fly to Rome in time, i suspect you are getting on a cruise? i always give few days buffers ahead of a cruise, and also monitor windy.com starting 1wk ahead of flight to make changes well ahead if need be to avoid the stress and anger you are going thru