So you’ve gone an entire lifetime saying these things with no problem, and then one day you encounter someone who’s decided to request “they them” pronouns, and youre going to drop this entire habit?
Did this person signal to you that you’d hurt them somehow? It sounds like they corrected an error on your part. Unless they displayed some anger or hurt, perhaps it’s just that you used the same pronouns everyone else does by virtue of how they present themselves, and then they corrected you, and you can use their pronouns from here on out.
I don’t think you should model this as a situation where you hurt someone. You used wrong info, got corrected, and you can move on.
Don’t start misgendering 99% of the people you meet just because one person corrected your assumption once. Don’t do that. Your cultural upbringing is not garbage to be discarded so easily.