Maybe what you need to do with your parents is see if you get to a point with them where the both of you and agree to disagree about religion. If that is possible.
From what I understand of his situation, that won’t happen. I know that not all Mormons are like this, but their households and communities are notorious for ostracizing people that walk away from the faith more so than any other religion in America. I’ve personally seen it happen to people I know.
As TV’s Frink would say, “Source?”
Yes, I know it happens. It happens with lots of religions. It even happens when atheists turn religious, though the switch is usually the other way around. I’d like to see some statistics that make Mormons so much more notorious for this than other religions.