I think I can identify with you. All photoreaders probably experience this on some level. It's possible that you may want to fail, in your subconscious, of course. If you did not acknowledge the concept of failure, it wouldn't exist in your world.
Anyway, the system is surprisingly simple. It's easily adjustable, and it's really easy to use. You can trust that your whole mind can do this! If you think you're going to fail, do what you can to prepare for it, such as by working on your thoughts first or getting proficient at deliberate relaxation.