How hard it is really depends on how much you retained from the prereqs. If you learned it well the first time, it isn't that bad. If you didn't, then you are looking at lots of studying.
I seem to remember that the actual chem section was easier than the Kaplan exam but Kaplans has big gaps in organic chemistry. The calculation problems are easier on the real thing.
If you are applying to schools that are on rolling admissions, it is better to apply to schools early. But even if you didn't, you just have more competition the later you wait. If your school isn't rolling admissions, it doesn't really matter that much when you get the applications in but it is better not to wait until the absolute last minute because it leaves more room for error if you encounter a problem with your application.
Try to relax. I'm sure things will be just fine.
