Quitting my job to focus on school?

I work at an accounting firm and I'm studing taxation as my degree. I work 30 hours aweek and basically I'm siting in the office all day doing nothing but answering phones. I have to keep a B average and on my midterm I received a 77 which is below the average. Im starting to realize that I don't have time for my family or my boyfriend. I come home and I study until I go to sleep. I can't do anything on the weekends fun because I have to study. Anyways it's tax season and i feel that working is to much right now. Do you think my boss will be mad or should I not care about what she thinks.