David,
I was fortunate to have had only one instructor during my PPL. His instructing style was however very matter of fact and abrupt, - if you were having an off day & your flying was cr@p, he would say, "you are having an off day & your flying is cr@p" (or worse). A lot of punters didn't really get on with him, found him abrupt and overly critical, and therefore did not enjoy their training.
For me, his (mostly constructive) criticism was water off a ducks back. At the end of the day - I wanted to learn to fly, & be competent & safe - and therefore if I was doing something wrong or was picking up any bad habits I wanted to be told. No point in pussy footing around.
However - just before my skills test, at the same point as you are now, I did a mini mock test with him to prepare. The viz was pretty poor so it was difficult on the nav & diversion practice to try & pick a distant feature & hold heading, so I was having difficulty in accurate straight & level. Without an obvious horizon, stalls & steep level turns also became more "challanging". Anyway, enough excuses - suffice to say that my flying that day was pretty poor (and my instructor made sure I knew it). I left that lesson feeling absolutely gutted, deflated and dejected. It took me a couple of days to snap out of it. I think my instructor was probably no different towards me than previously, it is just that you become so "wound-up" before your test and are so wanting to be built up prior to it that you become perhaps ultra sensitive to criticism.
After passing my skills test, I told my instructor how de-motivational that last lesson had been & he said that it wasn't uncommon for students to have a disasterous last lesson followed by the best flying they have ever done in their subsequent skills test. On reflection, I think he ought to realise that students needed more of a confidence boost prior to the test, but also that I was probably more p1ssed off with myself than with him for what I know was a poor performance.
Enough rambling - if you want to learn to fly enough, David, pick yourself up and go out and "show" your new instructor that you can do it, after all your last instructor thought that you were ready for test, and it is your examiner that you need to impress in a week or two not your current instructor. You're too close to throw in the towel now.
Mr. W.