How to quit a family business?

[Andre Quinonez]

So currently I'm 19 and a few months ago I moved to another city to work at my aunt and uncle's business. At first to me it was only a temporarily thing and I was working part time while I saved up money to move to my country's capital (Mexico City) to persue a career in music. But as time has progressed they ask of me to commit more and more of my time to the business. Currently I'm doing full time now and I live with my aunt and uncle so when I get home it's kind of stressing because all they do is interrogate me about the business. They also want me to go to college and study something related to the business like engineering and give up on the music idea. I plan to quit and move out in a month but I am not sure of how to adress it. My uncle has cancer, the business really needs work and my aunt is a bit emotionally dependent of me, so I don't want to make things more complicated for them. But what I fear the most is that they will try to hold me back and not let me leave because sometimes I get the impression they view me as I child who is unable to make decisions (even though I've already lived by my own before moving here). Any way, how could I tell them that I'm quitting and leaving without making too much of a family drama? Would two weeks prior to leaving be a good time or should I tell them about my plans as soon as possible?

Thanks for any responses!

Edited April 13, 2018 by Andre Quinonez
grammatical error

[Barbarian Number 8]

@Andre Quinonez They are planning to give you their business.

You could make a living of it and have music as your hobby.

If you leave, can they maintain the business or is all their efforts lost?

Can you survive by yourself with only your music in the capital?

What is most likely and realitygrounded...living of the business or the music?