Toney from Minnesota

My story is twofold not only do I need to provide care for my aging 78 year old mother, I also need to provide care for my 53 year old developmentally challenged sister. Doing this without placing them in any facility or separating them in any type of facility's. This is the wish that I promised my father before he pasted 8 years ago.
Truefully the only way I can keep that promise is to give up my life for theirs to leave my family behind and move the 2 hours away to take care of them. I have looked into the options and all are to expensive and unless she is 100% home bound Medicare won't cover it. They leave in a small town and don't want to move and after our last scare of medical emergency I have run out of options. They both need each other to survive separating them is not an option. HELP I don't know what to do I need to do the right thing but the choices take away my life to support them.