There is this very common idea that science and math, as taught in high school, are hard except for a couple of natural geniuses. Certainly, not everybody is equipped to become a Ph.D. scientist, but the myth of STEM being only for the chosen few is really an indication that most math and science educators just aren't doing a very good job.
A quality bachelor's degree in math and/or science education (you may choose a specialization, or combine both) will set you apart from the herd. Getting such a qualification in Europe, where pedagogical theories are not as assembly-line orientated as in the U.S, will make you even more employable.
A degree in math or science education typically also includes training in areas far more advanced than those your future students will have to learn. This serves a dual purpose: it makes it easier to answer the dreaded question "Why do I have to know this?" and ensures that you have a firm grasp of all the material covered in high school.
In fact, a degree in math or science education contains many of the advanced courses a regular B.Sc does. There is also a teaching component to the curriculum, which generally includes about a semester of practical classroom exercise. This could easily be thought of as something tacked on just to let students qualify for their teaching licenses, but that would be a mistake.
Teaching is about more than enabling young adults to pass some section of the SATs. Teachers serve as role models, but more importantly demonstrate - formally or just by example - the importance of a good work ethic, communication skills, critical thinking and problem solving, and leadership.
Teaching well also requires several skills most people just don't possess naturally. Learning these and getting the opportunity to practice them under experienced supervision will make you a much better teacher. With luck, you may turn out to be one of those who make math and science seem easy rather than arcane.