When a teacher flips for the first time, students are put under the microscope and they hate it…at least in my experience. They have to unlearn how they have been learning playing school up until your class. Needless to say, student surveys usually do not go well the first time they are asked about the new style.
Do not define your teaching by the grades of your students.
Do not sacrifice what you know is right for your students because of a number on paper.