Average is kind of meaningless unless you consider yourself average? It sounds like you are taking a lot of intense classes, more than the average student. I would only take what you want, what feels healthy and doable to you.

What are your goals for the courses you are taking? I had AP European History (I have degree in history) but think I would have just taken something else rather than the AP if I could do it again. You get to college and the difference between taking "this" course or "that" is not so great, especially in the first couple years. With my 20-20 hindsight a lot of the pressure in high school relative to college and the future, etc. is self-created or put on one from others' expectations. I wish I had been able to give it more thought and made some goals about exactly what I wanted. I did not pay attention to the math and missed out 20 years later when I wanted to do computer programming. I had a gift that made accounting a good fit but I did not learn that until I was 40. Getting into college was not a problem, what I want for myself and how to figure that out, was.