How about if after 36 hours, you're still flying circuits your instructor tells you are 'pathetic'. Is that code for 'Give up'?
Unless you are on good banter terms with your instructor I would take that as a pretty negative statement from your instructor - not at all constructive. You shouldn't have to be concerned if it is code for 'give up', if the instructor is of any merit then they will also be able to have an honest chat with you.
As for time to give up - well, I'll restate what has been said so often before. It is tough and hard at times, I almost felt like quitting on my PPL(A) at around 35hrs - I started to have a crisis of confidence in my ability in all areas (circuits, landing, R/T, nav...) but pushed on through and qualified last year. It *does* all fit together eventually.
I'm now a single-hours rotary student and still get tense and think too hard about what I'm trying to do - the secret really is to just relax and it will fall into place.
Keep at it! It is worth it in the end
