What does “horrible at math” mean?
You have to be good at math, but not necessarily great at math, to do well in engineering. Do not be discouraged because there are a few people who are three or four grade levels ahead in math (e.g. calculus BC in 9th or 10th grade), because they are outliers.
Also, math is like many other subjects in that disciplined learning and practice will improve your skill at it; your skill is not fixed to innate ability.