If your parents really think it's that bad, they won't agree to your marriage. They told you this just to hope that your future marriage life will be happy and that you will not be wronged by following him, so as to warn you.
But really, you are married, and your parents must wish you happiness with hope, and there will be no other thoughts.
So don't be sad ~ all parents are the same, it doesn't mean they disagree, just want their children to be happier. Prepare for the wedding ~ not necessarily stupid girls are unhappy ~ the simpler people know what happiness is. Bless you!