Hi Andilynn,
You've already gotten great advice, and I just want to re-emphasize that you should not be shy about talking to your professor during her or his office hours. Take advantage of that one-on-one time, and explain any worries or fears you have. I'm an English professor at a community college, and I'm always happy to alleviate any fears that students have, esp. those that have been out of school for awhile.
You might also ask your prof if she or he can recommend a good grammar handbook for you that has APA format in it. I personally really like all of Diana Hacker's handbooks (published by St. Martin's Press), but there are many great handbooks out there that should contain a section on how to properly format research essays in APA format.
Also, several people suggested contacting your school's writing center, and that's a great idea. Most writing centers offer free tutoring, and many have free workshops on writing research essays. You can bring in rough drafts of your essays, and have them look them over.
As another piece of advice, it's probably too late to sign up for another class, but I'd recommend taking a writing class (English composition) as soon as possible. Even though your comp class will most likely focus on MLA format, you will learn really useful info about writing essays. One of the biggest things I focus on in my comp classes, in fact, is breaking down the writing of essays into several steps so that they become more manageable and, hence, less stressful.
That's great that you did so well last semester! Hope that this helps!