I'm not the daughter I'm the granddaughter. How can I balance this?

My Memmy means the absolute world to me, however it seems like none of my aunts or uncles want to take responsibility and it falls on me. She calls me day in and day out. My Memmy is 84 and I am struggling to regain balance in my own life, losing time with my other half, can’t work as my Memmy demands my attention until my Pappy gets home. I cannot afford a home because when I did work I would have to call out to take care of her. How can I balance this. I'm so stressed and no one else in my family seems to care.  I don't like wiping my memmy's butt. But they are against hiring an outsider.