Mighty Gem is right; 6000 hrs and you will still hate check rides. The only way round it is to take MBJs advice; Play hangar pilot with the FLM before each and every every check. Why do you feel that you fly better with your instructor? Because you are safe in the knowledge that you can't cock it up - He is your mental safety check, when you are on your own your brain is working at twice the rate to make up for it. You will improve with time and experience.
Gotta agree with Helinut. Some of my previous examiners for LPC/OPC have been brilliant, you feel at ease and you learn from them. Others, it has to be said, are crap....