Caring for my Mother....

....that has terminal stomach cancer. Feeling very up and down and don't know what to expect or do some days? My mum has been ill for nearly 3 years and had her entire stomach removed a year ago, but now it's back and spread with no further treatment available. She is being amazing and strong, I don't know how she does it? She is 70, I am 45 and will have no one left when she isn't here anymore.