Do I need to make a choice?

I'm in the marching band right now. Marching band's practices last longer than other activities' practices. I could work a really great job but I'd have to drop marching band so I could get to work at 5:30. I'd work Sun.-Thurs. from 5:30 to 10:00 and make about $1000 a week. I feel like shit whenever I ask my mother for money for gas or food. My mother told me I need my extras to keep me balanced. I could have extras like class council and SCA, just not marching band if I took this job. She says I don't have to because we're applying for social security disability. I just feel sad and helpless and like a fucking leech.