How should I handle family members that do not help out much with our mother who is up in her age?

I moved bac from FL to help out with mom. I am staying with her 24 hours day, 7 days a week. I have been bac from FL now for almost 10 months. Once of my stipulations to coming bac was that I have at least a week off each month to my self. This has not happened. My twin brother is does not c all or stop over as he has a drinking problem. My oldest sister health is not good and her husband helps her out. My other sister's health is great and she has a married boyfriend that helps her out. Since I have been back my health has gone done hill to the point where I have been in the hospital twice now. I am no longer on pain meds to help with the pain that I am in. I am running a low grade fever and my right side is in pain constantly. I can not eat regular meals as my throat has quit working. The doctors think my liver/gallblatter etc is messaed up. I can not get into the dr until the 20th. I have lost over 20 #'s. So I weigh about 100 lbbs. right now and it is hard for me to help my mom out considering my health is not good. When I came home from hospital I call my sister who's health is great and told her that I can not do this no due to my health. I have no one to take care of me except myself. I am no good to mom if my health is bad. I also mentioned that she needs to talk to mom more and spend more time with her. She can talk to her bf for hours on the cell but can not talk to mom. I informed her up how this hurts mom and how much mom's health has gone down hills since I have been back. I told my sister it is selfish of her to not help out more than she does. She thinks by taking mom to the dr here and there is her way of helping. I told her it is not the same being with someone 24/7. How can I get certain family members to pay more attention to mom. I have decided to get a place of my own so that I can focus on getting myself better. Is this wrong? It seems no one cares about mom or I and our health.......... Please tell me what your thoughts are and what u would do if you were in this situation...