Common Sense versus Freedom of Choice?

My mother refuses to go into aged care accommodation or move to live with me. She has cancer and last August was given 6 months to live. She barely has the strength to perform her own personal care these days. She is clearly weakening and can hardly lift her feet to walk. She falls. She has no strength left in her hands and has been going to the neighbours just to get the top off her tablet bottle. (She refuses to have the free medication blister packs). Called Webster Paks in Australia. I am her Medical and Financial POA. I supported her choice to remain living in her own home until now. I have been accompanying her to monthly doctors appointments where all she does is deny the obvious cancer symptoms, e.g. pain, exhaustion, weakness. But later complains to everybody and anybody. She has had cancer for 8 years and has largely refused treatment. I can no longer reason with my mother. Last December she agreed to call me if she felt severely ill,weak or in pain. Now I only find out days later when she smugly informs me that she had a "bad day" some days ago. She even said she had a plan to die at home. Alone ?? This I feel, I have a duty of care to prevent. I have "stepped back" and tried to allow events to unfold but the anxiety I am now feeling is getting me down.