Need Advice

I started SD in my LTC facility in April, I do the scheduling, supposed to do training, inservices, orientation, infection control, work the floor when someone calls in and go back to school and obtain my RN. At the moment the schedule is consuming me. Everyday something comes up, either a nurse or CNA will call in. The staff more or less tells me when they will work. They have been allowed to get away with this and it is driving me crazy!!!! The DON plays with the schedule, gets vacations screwed up, then when checks come out, staff yells at me, because "I" do the scheduling. I spend more time trying to fill in shifts than anything. I've never done anything like this before. Am I in over my head or is it like this every where? Infection control was dumped in my lap earlier this week with a quick 10 minute overview of what I was supposed to do and was told that part of it had to be done that day. I don't have time to do anything but make sure the floor is staffed at this point. I took this position mainly to get off the floor because of some health problems, but golly gee, I don't know which is worse, the pain from the physical work or the extreme mental stress from what I have been subjected to so far. I don't know what to do. If I schedule somebody on a day they don't want to work, they just call in, which in turn, makes it that much harder on me. The DON has written people up, but it doesn't seem to bother some of them. It's like there is no work ethic anymore and nobody cares about there job or the residents that they are supposed to be taking care of. The main ones that do this, when they are at work they are good, it's just getting them there when you need them. Somebody please give me some advice I'm sinking here!