I actually love music a lot, but I am going to have to put that aside for 2 years. You need to do the same since music will not guarantee you success you will need to have a backup. Going to university can help you achieve your dreams of becoming a musician. There are more opportunities than high school, new doors will open up for you. If you can achieve your goal of becoming a musician by the time you finish uni you can just leave and never graduate however graduating will grant you with a backup plan. So if things go wrong you will have a diploma and you will find a job eventually. You could also consider going to a conservatorium if you really love music that much. You will need to take it very seriously and professionally. I am not sure how seriously you take your instrument or you might just be doing it for fun. You can be a music teacher, or maybe play in an orchestra (I doubt guitarists can do that though lol). Anyway, I wish you all the best. Just do what you love to do but try your hardest to reach it. If you wanna be a guitarist or a musician, you will need to practice all day, every day. If you want to get into a specific degree you will need to study all day, every day. The only way you can reach success is to work for it. But whatever you do, don't leave school as I am sure you will definitely regret it. Don't give up, and work hard towards your goals. I can never work hard for something if the thing that I am working for will never be what I love and dream to become. So if you don't know what to do in university and want to become a professional musician, you should consider going to a conservatorium. My opinion is if you are into rock and that type of music, then you should get into a degree that you will somewhat enjoy, use university to get into bands and from there your band might get gigs at local cafe's and eventually you might become popular who knows. And finish your degree just in case. And use that as your vision to study.
I love music more than software engineering, but I music will always be my main hobby and I will take it very seriously and I will also probably form a band too.
P.S I hope I helped
P.P.S - Feel free to PM me
EDIT: Wow, this is pretty long.