David,
You should also maybe remember that you also have the right as a human being to tell somebody exactly what you think! I have been really lucky with all my instructors and they were all extremely patient and quick to praise you. However if I was having an off day they would say, sometimes in no uncertain terms.
I understand exactly what your saying and I have had many a lesson with episodes something like the following:
Instructor: You've lost 350ft in the last minute! keep your eye on the altimeter
Me: I'm trying
Instructor: Watch your heading, your miles off, and add some more power before you start climbing
Me: !!!!!
Instructor: You've just sailed passed 2500 on your way to 3000. We should have levelled off at 2500, and watch your heading.
Me: This is p*ssing me off now
Instructor: Relax, stop trying to fight everything, you're like a bull in a china shop. Whats your estimate.
Me: Ummmmm, errrrrrrr, ummmmmmm
Instructor: Do you know where we are?
Me: Ummmmm, errrrrrr, ummmmmm !!!!!.
etc etc etc.......
This can all be extremely depressing, and I think we all go through it. Don't be frightened to say to said instructor that your not having a good day. If you feel he's really being unkind, tell him!
I agree with Mr Wolfie. Your next lesson might be the best you've ever had.
If its any consolation I don't feel particularly "receptive" when I know I could be doing something better and I've got somebody else telling me. I know, and its very easy to walk away............Its also a great feeling when it all comes together and you can tell your instructor to "put that in his pipe and smoke it"!
You've come too far just to throw the towel in. Buy your instructor a cup of tea. tell him how your feeling and why, and be prepared to take a bit of abject critisiscm on the chin. Maybe its also worth remembering that the more your instructor wants from you, the better your flying will be, and the easier you will find the test.
The very best of luck,
F - Wyg