What would you do in my case?

Hey guys. I'm 19 turning 20 in November and I still live with my mother. I work 2 jobs (one at JCPenney and one at an after school program) I also go to college full time majoring in Psychology. Now I have been attending piano lessons for 10 years and guitar lessons for about 3 years and I don't want to give it up because music is a pion for me. If I give it up I feel like I would be giving up a part of myself but my mother doesn't seem to understand that. She says to give it up, stop wasting my money because it's doing nothing for me, I'm wasting my time, only little kids are supposed to go to those etc. I understand that she wants the best for me and I am respectful to her and don't tell her to shut up and those type of things. She went through a similar situation where her sisters were doing to her what she was doing to me. How do I make her stop pestering me about giving up music?