Don't worry, no need to be sorry, Italian as a language is "tough" for a foreigner, or - maybe better said - once you get over the basics (which appear simple)it gets nuanced, and - generally speaking - Italians tend not to correct too much foreigners as long as they can understand them.

Besides the fragmentation you noted, you have to add also the language one, even if today almost anyone can speak and understand Italian and normally uses it, in many areas local dialects are still widely in use, often partially mixed with Italian, to the point that the Italian you learned from a girl from the north, border with Austria, will be (slightly) different from the one you would have learned if she was from - say - Rome, both for the accent and for the use of one word instead of another.