Fear of Failure

Here's the deal, I'm a first semester nursing student who is afraid of falling on his face. I've busted my butt for a year getting in, everybody I work with at the hospital is rooting for me. My family is rooting for me. I've visualized myself being a nurse for the last two years, so it seems that there is alot on the line for me. After going through the Orientations, I've realized that there is a chance that I could fall on my face. For instance, we have three opportunities to pass our Drug Calculation Exam, and Math has always been my weakness. Also, we have three chances to pass the check offs in lab, and they are Injections, Catheterizaton, dressing changes, and several more. We did adminstration of topical meds today and I learned that there is a mountain of details in just giving PO meds.
Ironically, I'm not worried about the Lecture exams, I feel confident that my reading and studying will pull me through, plus I've never really suffered test anxiety. But the dosage calculations has me scared of failing. Anybody have any tips? I really want to succeed at this....