Having done many certificate and proficiency checkrides over the years, I have come to believe that the role of the examiner is more about assessing judgment than determining that a candidate can fly every required maneuver at exactly the required level of performance or better. The DPE's and FAA Inspectors I have flown with have been typically very senior people who have seen it all over many decades. These guys have developed some skill is determining who can get the job done safely and who cannot. My certificate checkrides have been low pressure events (except for the self imposed pressure) with the oral portion rarely more than an hour and the flight portion requiring a sample of the syllabus maneuvers, not every maneuver in the book. As my current instructor (also a gray hair with 20,000+ hours in helos, and a flawless safety record) recently said, "when I sign you off, there is no question that you know how to fly; the role of the examiner is to test your judgment." One examiner said to me at the beginning of the checkride, "Relax - lets make this fun," and another, "I can tell on your first pick up whether you are likely to pass or not." So, it may be productive to consider selecting another examiner.
Not a lot of margin in the R22
This is another part of the story. For reasons of economy (apparently) most helo students start training in what may be the most demanding helicopter in the light helo fleet. There are those who might argue in favor of this, but my logic says start in something much more pilot friendly and progress to the more challenging as skill and experience grow. Kind of like starting fixed wing training in a Pitts instead of a C152.