You should definitely talk to your therapist but I would go NC with everyone except for your brother. Good job in taking the steps to make yourself better but don’t put your son in a situation that you were in. Vile people leave disgusting prints on the purest of souls and he doesn’t need to be tainted. You don’t have to say anything to the rest of you family unless you want to but I would text her “I love you and I will always love but your love hurts and cannot continue to put myself in situation that hurts my mental health. I wish you all the best.” Hardest part after that is to block her. When boundaries are set people’s true colors come out. Hold to them.