Driving instructor problems?

Focus on the driving, not the instructor. Yes, it helps to have a good instructor, but ultimately it is you not him/her who will be driving for the rest of your natural. It sounds like you know how to drive, you just have difficulty translating what you clearly know into practice. So, my advice would be to try and spend some time with either friend or family who already has licence just so you can get some experience on the roads, without the pressure either financially or otherwise of an instructor being in the car. Then return to a driving instructor either the same one or a different one, once you have regained some confidence so you can brush up on the technicalities necessary to pass your test!