So you haven't taken any college math? You'll have some catching up to do. Your typical engineering degree is going to have you go through three semesters of calculus, one of differential equations, and one of linear algebra, plus a whole lot of classes that rely on your knowledge of those subjects. I'd say take calc 1 at a community college (or even one of those free online things) and see how you stack up. If you can get a C without much effort, then you're probably good enough. If you can get an A then you're definitely good enough. It doesn't take a genius, just someone who's proficient.
Being someone with two years of college credits that aren't transferable to an engineering degree means that I'd probably have to spend another three or four years in college, right?