Ok so what I'd recommend is that you look at Khan academy courses. They are all free and very well presented. Precalc and Calc 1 should give you the mathematical tools you need. Basic physics and after that AP physics will get you going in the physics department.
If you want to get your hands dirty actually coding a game, try and get your hands on a book discussing game physics. This looks like a good place to start. Keep in mind that you won't have the math/physics to deal with all of the material in the book to begin with, but that should give you a good idea of what else you need to learn (from online sources such as Khan academy) as you go along.
Hope this helps. Good luck!