What a sad and ugly situation. I’m so sorry you have been tormented for so long. I don’t have a way to know whether you are a sociopath or not. What I do know is that this woman has intimated her whole family to the point that no one is reaching out to you to help you. Even you aren’t helping you. At 40, you shouldn’t have to move in order to deal with a sister who you think is off base and out of control.
I suggest you talk to two professionals: a therapist and a lawyer. The therapist will help you determine whether there is any truth to your sister’s accusations. She will then help you figure out how to handle the situation so you don’t lose relationships with your friends, your coworkers and your son. You need some practical strategies for managing the situation. You also need the support of someone who is definitely in your corner.
You should also talk to a lawyer about what your rights are in this circumstance. I can’t advise you because that’s out of my area of expertise. There may be legal mechanisms to stop someone who is harassing and stalking you — even if she is your sister.
I hope you will follow through, especially since you think your sister may drive a wedge between you and your son.
I wish you well.