You learn from trial and success. Not trial and error. Two or three instructors is about the right number, instructors are human and can have a bad day. However, you need to accept that your opinion may be wrong.
Have you asked if you can video a flight? Fixed camera, of course. Get your instructor to demo an approach first, then continue with the lesson. Watch the video and see what is different when you do it.
You might also ask to take a break from circuits and do some navigation, then go back to the circuit.
Remember it's supposed to be fun.