If you are a good writer, you can always try writing them a letter that explains it perfectly.
I always liked letters because I could express my point entirely from start to finish, without being interrupted. Most of all, it allowed me to maintain a degree of calmness that isn't always possible in face to face conversation.
The only thing I found awkward about letters is the handoff.
Anyway, just wanted to throw that out there in case you might think it could work for you too

Good luck. I'm sure if you remain calm and polite about it they will have no choice but to consider changing their ways even if just slightly. If you come at them like a victim, they may not be so responsive. All depends on your relationship with your parents, which you know the most about!