How do you get someone to eat and drink?

My mother lives in an ALF..I am her only child who lives four hours away. Last June she would not eat any of her lunch except for ice cream. I talked to the staff who told me this started about a month ago. Since then she has not been eating or drinking. She has had blood work which is good and checked for a UTI which was negative. Since May she has lost 36 pounds. The Dr. put her on an depression medicine which also stimulates the appetite with no results the medicine was increased and still no results. Someone sits with her to make sure she drinks 2 bottles of Ensure each day. The Dr. called yesterday and told me if she doesn't start to eat or drink she will be put on Hospice. To make matters worse, In September I was diagnosed with a brain tumor which had grown into my eye socket and eye orbit.I was in the hospital for 2 weeks. Thankfully the tumor was benign. However, I am having a lot of vision problems and I can't drive. I feel so horrible about not getting to see my Mom. Does anyone have any suggestions?