Anita Porpoise

Worrying and stressing about your mother does no one good. And it can lead to a decline in your health. And if that happens there will be no one to care for your mom.
You will not be a horrible daughter or person if you do not care for your mother. And care is not all or nothing.
Depending on your mother's age and finances you can sit down and work out a plan for her care. If your mother owns her home or has savings you may want to sit down with a trust professional. If mom can make funeral arrangements ahead of time that would also be helpful, but if not it might be something that you can look into now while no one is dead. It is much harder and cost more if you wait to the time of death.
Does she have any long term care insurance?
Doing all of this helps YOU and your mom.
You might want to talk to a Social Worker, lawyer and people in the Senior Center where your mother lives, they can provide a wealth of knowledge and resources.