You should not beat yourself up or doubt your NCLEX abilities based on the diagnostic test! I did not score as high as my classmates on it and I also failed the Predictor test the first time but I just took my Nclex on the 29th and passed with 75 questions! The Q banks and question trainers are what you need to focus on. I averaged about 58% on them, but I made sure to re-mediate the rationales and I did fine. I graduated on July 31 and started studying from Aug 4-28th and I improved so use the diagnostic as a study point and don't let it discourage you!