Help... Calling into work

I've been working at Walmart for 2 months. I'll only be there one more month, maybe less because I'm starting school and plus their very unfair there and treat me like I'm dirt, I just look past it.  I wanted to call out tomorrow, I need rest, seriously, I've been working 6 days straight, 8 hour shifts, sometimes until 12am and they only give those shifts to me, I told her I didn't want to work them when she asked me. I wanted to take tomorrow off so I can have it to me, I've been really stressed, I can't sleep, I barely eat, my head always hurts everyday all day, I feel like I'm in sort of a depression. And plus I have a lot of stuff going on with my dad having cancer and getting very sick. I'm just physically and emotionally drained. I just need time to myself. I've already taken one day off last month because I had strep and didn't want to spread it. Would it be to much to call in again ? I'm off Thursday & Friday but I have college orientation to attend so it won't really be a day off.