cde certification

I have been involved in teaching diabetics for the past 5 years, I love what I do and am told I am good at it, I am not based in a clinical setting. yesterday I was informed that I had failed the CDE certification. I signed up for the exam in June and was not informed until the first week in October that I was approved to do the exam. Next I was not able to find any preparatory books to purchase or any preview classes In South Florida. I am sure some exists. I asked diabetic educators and they said there were no preview books. I know there must be some somewhere. For me not understanding the format of the examination was my downfall. I did not realize the exam was akin a PA or an ARNP exam however, all the questions were related to Diabetes. Could some one assist me with locating resources that will help me . If I am going to be able to retake this exam in March,(At $350 )I need to be better prepared and since one cannot hope to study everything in the time available I would appreciate ome help. I am an BSN prepared and graduated second in my class so I am not without some knowledge.
Thanks.
Med.