Hello, I'd like to help you with your question.
It sounds like your mother might have a personality disorder. When someone acts as she does, hurting you, blaming you, etc, it is likely that she suffers from a personality disorder.
Personality disorders are typically ingrained behaviors that someone develops, usually in response to being raised in a dysfunctional or environment of some sort. It can also have cultural influences as well, though it is mostly about how she was raised. The person could not get their needs met (for unconditional love and attention) so they developed other ways to get what they needed which usually involved dysfunctional behaviors. When they grew up, they continued these behaviors even when they were no longer needed.
Knowing what your mother might have and how to react to her behavior can help. While there is no way to diagnose her without seeing her for an evaluation, the behavior you describe sounds like narcissistic or borderline type. Here are some links that can help you figure out what she might have:
Unlocking Your Family Patterns: Finding Freedom From a Hurtful Past by Dave Carder M.A., Earl R. Henslin, John S. Townsend and William Henry Cloud
Many people can have some traits of one personality disorder or they can have some traits of a couple of personality disorders. By finding a personality disorder that seems to fit, you can at least know what you might be dealing with.
When dealing with someone with a personality disorder, it is helpful to keep in mind that they are not reacting to who you are as a person or even what you are doing. They are going by cues they learned long ago on how to relate to their world. And their responses can seem overwhelming and out of touch with the actual situation. They can also be very hurtful and hard to cope with. Your mother's focus on you can be a symptom of her problem. It is not uncommon for people who have a personality disorder to pick on one person as a target, which is similar to bullying
If your mother won't get help or change in any way (common with someone with a personality disorder), you may have to change how you interact with her. One thing that helps is to see what she does as about her own issues and not you. Also, think of one phrase you can say to her that neutralizes anything she might say. such as "I'm sorry you feel that way". That usually shuts down the person and you can make a quick exit out of the situation.
You can also talk to others who are trusted friends or family. Let them know that you have tried to help your mother, but that she continues to have issues. Ask them to tell others that when the topic is brought up about what your mother says in public. This can help you protect yourself and your reputation.
I hope this has helped you,