I hate that saying , it's such a cop out for the failure of a parent, in my country it has multiple variations "Be the horse rider, not the horse" being one of them. It's honestly such a tragic thing to hear from your family. Want real advice that might work? focus on homework and get as much independence as you can, do not let him do anything for you, that way , if you plan to go on with life, when you'll get your diploma you can start your first job and maybe try to find somewhere to move away from them without your parents saying anything to you "you owe us this or that", you didn't describe him but he sounds like a narc.
You need to learn how to do things your own and start alienating yourself from them before your brain completely forms, if your brain forms in an abusive household and they have their grip on you (ask me how I know) , everything will be 50000 times more harder than it is, you will always second guess yourself and have a sort of codependency that you can't get the fuck away because your brain is associating your abusers with family.
But it depends on how your early childhood was, I'm not trying to be dismissive, there are cases , where what I described might not be possible for a myriad of reasons. There is another way you could get help, and this might be the more likely option, try to contact your school's psychologist if you have one, you can talk about these expectations, try to explain to him maturely what you want from life , or at least lie in the most honest way possible "I do not want to be a musician, I want a simple life and I want to know how to not let my father's words affect my mental health so I can save up money and move out to rebuild my life". (edit: you need to talk to him because he is a designated adult and one of the only people who might be able to help you, your extended family might take your fathers side so please try the school psychologist if you have one)