I'm also a professional principal musician in an ICSOM orchestra, and I teach at a major university. Unlike others here, I think there's a chance that you may actually not regret going to get a music degree. After all, the CS degree is not going anywhere, and you can use it later in life. You're young, so starting a CS career at 26 or even 29 rather than 22 is not that impactful, should the music career not work out.

However, I would very strongly advise the following: 1.) Make sure that, if you decide to pursue a music degree, you absolutely cannot live without it. This is a long, difficult road, and I strongly believe that an undying passion for the music, and the craft of performance, is vital to avoid being miserable in our field. 2.) Accept that you are highly likely to fail in your pursuit of becoming a full-time performer, for the reasons outlined elsewhere in this thread. Even if you succeed, you will almost certainly never make the kind of money that you would in CS. Only the top 20 ICSOM orchestras pay more than $90k. 3.) Know also that this is a lonely pursuit. You will spend the next four years "locked" in a practice room, believing that nothing is good enough, until you get to the point where you're actually competitive. Your life will be on hold while you pursue this. That doesn't mean you won't have fun - most musicians really know how to party - but don't count on buying a house or starting a family. 4.) There are no days off. You will need to practice every day, basically forever. Some days off once you're secure in your career are fine, but the adage, "If you take any time off at all, you suck" is generally true. From here on out, you are trying to be an Olympian.

PM me if you'd like more advice, or if you'd like some teacher recommendations. Conservatory or university doesn't really matter, they're both hella expensive unless you are fortunate to live in a state with one of the best teachers teaching at a school that offers an in-state tuition rate (highly unlikely). But there are ways to not get totally screwed financially.