Question about med surg

I am in my 2nd semester, 1st 8 weeks. I just got a D in the med surg class. I will go right on into psych next week and then after summer break I will take the class over again. Very devastating. My question is, are all ADN programs the same? In 8 weeks we covered I.V. therapy, communicable diseases, immunization schedule, general assessment, children assessment, G.I., Neuro, Fluid and Elec, Renal, skin disorders, and then 2 days before our final, which was 90 questions, we covered hematology and oncology and there were 50 questions on the final covering just that info. We only had really 1 1/2 days to study hem. and onc. Is that normal?? That is what kept me from passing, I concentrated so hard on learning hem and onc that I did not have time to go back over the other material and refresh.