I’m so sorry you had to endure such a thing.
This was a confirmation Mass? Then I suspect many of the people there were not Catholic, but friends and family. They don’t have clue one how to properly behave (obviously) - but shame on the Bishop for not asking for some respect if it was that bad.
When my Dad was finally confirmed this year it was pretty close to the same thing - people talking everywhere, not paying attention, it was just so sad and infuriating.
Hopefully this is a one time thing and you won’t have to go through this again at your parish. You were totally justified in being angry, I would have been as well.
~Liza