It is a difficult situation when a parents refuses medical treatment . It will be helpful to try and get someone that your Mom trusts to evaluate the situation
and see if she is competant. How is her mental status? Will she allow "Certified Home Care" to visit her. If she will , Medicare covers those services and her doctor will be willing to request it.
Most of all, try and get a handle on this difficult situation by getting her nursing or medical care in the home if possible.
Step one will be to contact her doctor and ask for advice. Then be sure to get support for yourself and the stress. Try and find a way to get Mom to see the importance of basic treatments. You need to get local ,credible and individual advice to solve a very difficult situation.