It is unfortunate that your mother's situation has deteriorated to this point. It sounds like there are serious health and safety issues involved and that she needs intervention for her own well-being.
My first suggestion would be for you to contact your county's social services office, and inquire about resources they have available. Here in California, our county's resources would include Adult Protective Services, who have a legal obligation to investigate reports of neglect or abuse involving the elderly. You can also see if there is an Area Agency on Aging (AAA) available in your area, which would be knowledgeable about other similar resources.
Finally, you may want to simply call the police. If your cousin isn't taking care of her properly, and there are concerns about neglect or physical or financial abuses, those are crimes and law enforcement should get involved.
What an awful situation to be in.
The first attorney was right - find out if the local DSS has elder services. If not, you can notify the local adult protective services of your fear. It will be their duty to come investigate and if they agree, they will remove your Mother from the situation and place her into healthcare facility.
You cannot make her go, unless you are her legal guardian - which takes time and effort in the Court system.
Again, call the local DSS and APS (adult protective services) and if they can't help and it gets worse, you may need to apply to be her guardian.
Again, I am sorry - best of luck.