In your shoes, I would not have been able to keep quiet. I see you're getting that advise quite often. Hey, you've got a little over a month to go. Squelch if you can, but otherwise let 'er rip. At least you tried. Maybe the seeds of doubt you've sown will sprout someday.

Catherine, finish up yer education, get to uni and start a new life. You'll make new friends and a new life. Be brave x

Don't waste your energy. It won't matter. Finish your time and move on. Find some friends with open minds and see the world.

I would only bother continuing with the conversation if I saw some form of thought or reasoning from the other party. If you're only getting a strong negative push back, these may not be the type of people to try and have a reasonable debate with.
Just my two cents.

Eventually you will learn what fight to pick and what to just tag along....... Live and let die