How do I gracefully quit my job I've only had for a month?

I have hated my job from the first day (I'm an esthetician istant to a spa owner) but I have stayed there for a month for a variety of reasons: I feel bad that I'm the only other person there to help my boss out, maybe it'll get better, maybe I'll learn something, but honestly, I absolutely hate it. I work 10-12 hour days for a bit over minimum wage with no lunch break most days, I am supposed to be her istant but I do the job of three people: maid, receptionist and istant. So why am I still there? I am conscientious to a fault and a people pleaser. I hate it when people are disappointed in me and I hate confrontation. I would hate to get a bad recommendation from this person, even though I work my off for her, although she has gone through 5 people in the last year. It's not the type of job where I can submit my resignation letter because it's just the two of us. BTW, she has no idea how I feel. I act like everything is fine. :(