Want to leave job but made verbal agreement to stay until June am I allowed to leave without any repercussions?

I work in fast food and I am an assistant manager and I made a verbal agreement last June to stay for a year. I’ve been taken advantage of through scheduling, I’m working way more than I agreed to and am getting forced into work when someone doesn’t show up. Not to mention my boss didn’t even finish her first year of high school so she is not qualified for her job at all. I just don’t know if I can leave without legal repercussions if all I did was say I would stay for a year.