Psychology Research Paper - APA?

I'm a freshmen in college and currently taking Abnormal Psychology. I needed a summer class and this 4000-level course was the only one available. My professor has assigned an 8 page paper due in 3 weeks (in addition to the studying/exams every week that come with a 6 week course). The assignment is to pick a disorder and write five pages about it (symptoms, history, who is more likely to have it, treatment methods, limitations caused by it, impact on society, etc.), and three pages about my thoughts/opinions on the disorder as well as any experiences with it.

Problem? I've never written a research paper of this caliber, so I'm overwhelmed and don't know where to begin. I know very little about writing in APA format. How many spaces go between the running head and the title? How do you cite things (more specifically online things)? Since I'm not conducting an experiment myself for this paper, do I need to include the headings, abstract, and author's note? If so, what do I put under "Participants", "Methods", etc? What exactly are empirical articles and where can I find them that I don't have to login to view them? How do I cite articles that obviously have no pages? What are review chapters because my paper needs to have 2-3 of them not from my textbook?

I would appreciate any help because, as I said, I am very clueless, and my professor doesn't seem very approachable.