NTA. It is okay to set boundaries, or even to end relationships for our own well-being; family is no exception.

1. As we get older, we have the right to choose the relationships we maintain over our lives. Parents are no exception to this rule, especially with this kind of absurd and controlling behavior. People are allowed to believe what they want to believe, but not shove it down other people's throats. Some people are awful enough to do it to their children since children often have no other option and are easier to manipulate.
2. I know many might disagree, but you don't owe her anything. You didn't choose her as a mother, you didn't choose to have this relationship, it was one given to you when you were born and one you had to maintain in order to survive. If it is not good for your mental health or well-being, distance yourself; that is your right.
3. A relationship involves two individuals, her feelings aren't the only ones that should be considered because she chooses to cry about it and complain to her other children. If the only thing holding you back from cutting her off is the guilt she's trying to put on you, then all the more reason to ignore her.
4. *** I will say, however, when you do feel emotionally prepared to do so, you might find it beneficial for yourself to forgive her. Not because she deserves forgiveness, or to say that any of the things she did is acceptable, but once again, it could be best for your own mental health and well-being. There is a saying "holding a grudge is like drinking poison and expecting the other person to die". You can forgive her in order to be at peace with yourself and let her go, while not letting her back into your life. Forgiving her doesn't cancel out the fact that you still have valid reasons to ignore her. You don't have to follow this advice, but if refusing to forgive her brings you any kind of negativity or grievance, do yourself a favor and try to learn to forgive her.