Being a secondary school teacher, I have found some of the best turorial support comes from peers. If a friend isn't able to help you or if you need on-going support, consider contacting a counselor in your high school and asking for help in finding another student who can provide you the on-going support that you need. Usually there is a small fee for this support; however, a high school student who is good in math and science is generally much less expensive than an adult. And, you frequently can meet at school during lunch or after school and then take a late bus home. You could even try talking with your teachers to see if there is someone that they could recommend. Good luck on your search!
While we may not be able to comment on some of the other subjects you mentioned but for math u will have to brush up on your core concepts . More than advanced topics, what is important is that you cover the basics, and be comfortable across a variety of math concepts across topics. Then, it’s all a matter of practice and mastery.
I would suggest you sign up for one of our summer or year long programs at http://www.tenmarks.com/ – The best way to practice and master math. Cover math concepts one by one, at your own pace, and move on when you master one. Use our interactive worksheets to learn according to the structured curriculum, and hints and video lessons to learn on your own, on the fly. Plus, practice what you want, when you want, or watch our video lessons – at your own time, and improve confidence and gain mastery on skills – completely personalized for you as well.
All our programs are grade and state mapped, and a custom assessment sets up a unique curriculum for you if you want. You may also choose standard courses, spread over grades 3 – 10, for all topics you may need.