I'm sorry you're struggling

I can understand how you feel pigeon-holed into pursing music. My sister applied to engineering schools since she's a girl and a lot of engineering programs look to keep their gender ratios equal... and there are generally less females in the sciences. But she really struggles with her classes because while she could manage science classes in high school, I don't think she's truly interested in the subject matter nor is she inherently good at it. She has to work really hard to pass her classes. I know that a semester or two ago, she took a class that was really hard for her and she was ecstatic that she got a C because she knew she worked really hard, tried her best, and managed to pass the difficult class. Do you enjoy music? Or are you doing it for the prestige?
As for me, I'm majoring in English because it's the only thing I'm good at. I don't love my major. I find it hard to motivate myself to read and study since I'm not passionate about the subject matter. And I also don't know what I want to do with my English degree. I know I don't want to teach. And I don't know too much about other career options. At this point, I'm focused on getting through college and getting the damn diploma!
I don't know where you stand on your attitude towards music... if it's something you want to pursue because you love it or if it's something you kind of got sucked into doing. But I feel like it's definitely hard when it's difficult to switch majors... since you'd have to change your school. That's a big decision and I agree w/ Gayle that maybe talking to an on-campus guidance counselor, who probably has experience working with students with similar concerns, may be beneficial.
Sorry for rambling :/ I guess I was just trying to express that you're not alone in your struggles and concerns.