my school isn't going to finish our computer science course

I am in year 13 and lsat year (year 12) we only completed 5 modules when we have 12 modules in total. our teachers are not doing as much as they can, even though I go to a private school. I plan to start teaching myself, however because there is so much content, I don't think I can teach myself all of it. I am really worried because other neighbouring schools have finished the course in year 12 and now doing revision until the exams. what should I do?