It looks to me as if you have done really well in prescreens. Indiana, CIM and Eastman. Are you a glass-half-empty kind of person? And Michigan is a great choice too. Then you have your academic back-ups at these schools plus the other two. I think you are in good shape. Once your final results are in, you will have several options, and I think you were smart to keep them all open until April. (My daughter did that too, and decided between conservatory and college on April 30th, the last day!)
You can also keep in mind the possibility of a dual degree when the time comes.
I know how you feel about playing catch up with your instrument, and with theory. But late blooming happens too. Theory tests during audition time are generally truly placement tests, so don’t worry too much about that.
I think your decision to focus on music is a mature one, honestly, and I admire it. Please know that a degree in music is like any other bachelor’s. It does not limit you to one option for career, or one aspect of music either. It allows you to apply to any job that requires a bachelor’s, and gives you access to grad schools, medical, law or business school, and so on (with prerequisites, which can be done after graduation).
You can also work, volunteer or intern during your school years, if you have time, and gain skills related to the work world, music-related or not. My daughter had two internships in music organizations and gained skills that can be applied to any non-profit. We know young people with BM’s who are trying to make a living playing, and some who went to grad school. I know one who went into the entertainment business (agent managing artists), another who manages a theater, and one who is the development officer for a music festival. Music grads do very well with medical school admissions.
These four years really are a chance to pursue what you love to do and don’t have to be specifically vocational. But chances are, your prospects in music will end up better than you think if you work hard and work well with others and grow.
Finally, if you do end up going to the academic side of these institutions, you do not have to go with a major already decided. It is a really healthy thing, if uncomfortable, to have doubts about any path, including math. Take time to explore other subjects that you might not have encountered before. I know someone who was going to major in math but took a class in Russian, and ended up studying in Russia, and changed his major to Russian language and culture. Just a random example.
There are talented musicians who do a BA or BS in something else, continue lessons, practice and performing (in extracurriculars) and who still go on to good grad schools. It is a harder path in terms of development of your playing, but possible.
But right now, you are dealing with auditions and I don’t mean to muddy the waters. You passed at three great conservatories and have UMichigan too. This is a positive sign of your abilities.
I really encourage you to focus on these prescreens that DID pass you on to auditions. The rejections may reflect factors that have nothing to do with you. For instance, there might be only one undergrad spot for violin. If you love music, I hope you will continue and worry about employment after a few years of work. Every conservatory now has the same concern for its grads, and offer business or entrepreneurship classes, as well as gigs and internships. Go for it and good luck!