Changing from IGCSE to the American curriculum

I just finished my IGCSE exams in June and having some problems with my transcript. We just moved to the US and all the hard work I put into my IGCSE is not being considered. My new high school is placing me in 12th grade and I am only 16 years old and saying all my classes are level classes. This lowers my GPA a lot. I took English, Math, Biology, Chemistry, Physics, History, Business Studies and Computer Science and got 7, 8, 9 results. Can these results be changed to honors or AP standards? What should I do?