Bad bed, too poor to buy another.?

So my bed is terrible, and I mean terrible. I can feel the springs it and I can even hear them pop up as it gets worse. I also already have a bad back due to having a longer tailbone. (No I don't have a tail.) The thing is though, I live off of disability and food stamps because my grandmother can't move around and do stuff due to her health problems. I also can't get a job because I have a brain disease. Is there anyway to get make the bed better? My whole body is getting super sore from it and sometimes I wake up having issues walking from it.