<p>I have a similar situation - I’m also a female upperclassman looking to major in engineering. Although I enjoy math and science, I also love music (played piano for 10 years) and considered majoring in music performance for some time. I’ve actually found that having a “creative” background has given me somewhat of an advantage in math and science classes among my hard math-brained classmates, so do not be discouraged. I think you have as good of a chance as any at succeeding in the field. 
I don’t want to list too many personal details on this public thread, but I’d love to bounce ideas back and forth with you, as I think we have a lot in common. PM me if you want. </p>