How advanced are AP classes anyways? We don't have them in Canada. Electricity and Magnetism is by far the hardest courses I took in University so if it was anything like that then I feel really sorry for you.
Generally AP classes are just more advanced versions of the original courses. It varies from school to school as to what the actual curriculum is. In APUSH (AP US History) we had a great deal more depth in our studies than any of the other classes, even some of my college courses. We took the course for two years (first year starting with a study of the Native Americans and ending after the Civil War and the second year starting with Reconstruction and ending sometime after the moon landing) and read from two text books, an eight inch binder worth of handouts, a book report per semester and a huge project before the actual exam where we had to write a study guide for a portion of history (I got the evens leading up to the Civil War). It was all lectures from a podium, and I found them very interesting. It was probably more informative than any of the college classes I've taken thus far.
I also took APCS (AP Computer Science, which was just Java programming) and two years worth of AP English (Composition and then Literature). I opted not to take AP Economics or AP Government because they were more or less identical to the original courses with a great deal more projects/work attached for no reason. The AP English courses were about the fundamentals of writing a great paper and how to properly interpret different kinds of literature as well as a study of different literary eras. The standard classes were more along the lines of memorizing quotes from books and learning how to write in complete sentences (and failing).