If you are a lot better with engineering coursework, why are you worried that majoring in engineering will “tank your GPA”?
Like you, I was interested in both pre-med and engineering, and like you I’m not a fan of biology as a class, or rote memorization type classes in general. As such, biology was more of challenge to get A grades, rather than chemistry or engineering classes. I completed requirements in both, but decided to pursue grad school for engineering rather than medicine. You don’t need to decide now.