A few suggestions for you Cat.
Other AP courses I have taken closely match the course load and demand that I expect from college classes.- When you mention other AP courses that mimic a college course load, you should make the effort to mention some of those classes in order to prove your claim. Just mention the classes, you don't need to go into a detailed explanation of the course.
The statement that you have written is quite strong and thoroughly responds to the prompt. Aside from the extra information I am suggesting you provide above, the essay is quite ready for use already. At least that is my opinion :-) If you want to work anything else into the statement, just do so and I will help you blend it in to work with the rest of the paper.