My mother has Medicare and was agreeing to go for help at a place for an evaluation but recently changed her mind. Help!

Recently she changes her mind daily it's like she is very different since I have a brother won't speak to her but she is. The Dr. who had treated her for years said she needs psychiatric help because it's denial. I thought at first she had maybe dementia or Alzheimer's, but if she even hears sumthin she will claim to have it. I don't know how to believe her anymore and that scares me. How to know if she did get sick? She has Medicare and health choice. She also has her retirement and social security and survivors benefits. I've tried to explain. To her I would not leave her somewhere. I even offered to get as many counselors as needed here at home but nothing is good enough I feel. I am personally very beat down from this and I feel selfish even asking. What will happen when I gave my job up almost 5 years ago she agreed to pay off house idk what I need to guarantee payment there or how to get her help. Could someone please help me. Thank Yu