Have you sat down with them and shown them the Net Price Calculators? Have they seen the numbers? If they expect you to pay all that money, well, just say NO. They aren’t the ones who will be paying off your student loan when you are still 50 and hoping to buy a home or raise a family. Under no circumstances should you take any kind of private loan that leaves you with that kind of debt. That will doom you to a life much worse than working in construction.
You are 18 or will be soon. Yes, your parents support you but that isn’t going to last forever. At some point, you have to make hard choices and you have to make your parents understand that you are not willing to do things that will jeopardize your independence going forward.