PLease help! I suck at essays....

Could anyone give me some advice on writing a paper (in APA) on a case study? We have to write up a nursing care plan, stating 3 nursing diagnosis and choose one diagnosis to discuss. We then have to draw up a plan of care, evaluation (which we can make up) and an outcome. I have my ideas as to what i want to discuss, but, I am clueless on how to write this paper! I think I'm just thinking too much about the APA format and not about what I am going to write. If you need more info to help just let me know.....this paper is due this Friday (the 20th) and I need to get this done!