Should I feel bad?? :-(?

Ok so Im 18 started my 1st job in March at a grocery store as a cashier. I hated it and immediately wanted to quit. My mom and everyone else told me to stick with it for a while so I did. It's may now and i still hate the job..i'm not really a people person and the customers are rude, I dont really care for the managers, and It just stresses me out. So 2 weeks ago I put in my 2 weeks notice..without telling my mom. I was supposed to work today but my high school prom is tonight, which im not going to, but I told my manager that i was to get the day off. I told my mom that I didnt have to go in today because the manager thinks i'm going to prom. She was mad and said that I need tall the store & tell them that I will come in to work & that I lied...so I told her that I put in my 2 weeks notice & no longer have a job there. Now she's mad & saying that i'm 18 and need to be working. I mean it's my life not hers. And im about to graduate, i want to enjoy my summer before college. Was i wrong for doing what i feel was best and right for me? thanks :)