What should I do this semester with my two jobs and grad school?

So, because of several personal circumstances, I am in these huge predicaments that have to do with my two jobs and grad school.
I have two jobs (neither of which are related to my field by the way), and Im registered for three classes (Master’s degree). I was offered this other job on weekends, which means that if I want to take it, I might need to quit one of the other two. I need both jobs because I need $ to survive and I cannot drop classes anymore because the deadline is over (so if I drop a class I will lose 25% of my tuition). Plus, Im only 5 classes away from my Master’s degree.
My problem this: which job do I quit and which do I keep? Waitressing 1–2 days a week (which will make me anywhere from $200–400), my community organizing job 4 days a week (that only pays me $250 a week [non-profit sector]) and or hostessing on weekends (I might make $12–14hr).