Mother has given up

I’m needing some advice for my 68 year old mother. Over a year ago my mom stopped showing up to work. She used to be a workaholic and she just stopped going. She lives out of state. It got to the point where she stopped functioning. I flew out to her and helped her sell her house and got her social security set up. She got set up with a therapist and moved into an apartment. She has now stopped going to therapy and doesn’t visit my family near her. She just sits all day everyday and watches TV isolated and depressed. I’m unsure on what to do. It breaks my heart. I have no siblings and my own health uses. What do I do?