This is with a family member (sister). There is a history, of course!
I reached a point last year where I really needed to reduce contact with this person. I got advice about it on here and a lot of people said go NC, but I was trying to keep the peace in case of family funeral etc, I just wanted to be able to be polite and civil.
But she noticed this and started asking for more contact which I politely, but firmly said no to. She today then insisted on knowing what was going on and I tried very hard not to get into it and explained that with the history, I really didn't want to fall out with her. She insisted on knowing exactly what she had done wrong so I told her. Also slightly lost my cool and told her what I think of her which was not my finest hour. I may even apologise for being rude, but the upshot of our conversation was that I said I'd really like her to leave us alone. I tried being polite / civil, for the sake of family, but her saying "I've never done anything bad to you in my entire life" today made me so cross. She has done a lot of bad stuff to me and part of it is then gaslighting me later, denying she did anything, when I know she did, and then calling me mentally ill behind my back.
What do I do now? Block her? Apologise for rudeness but reiterate that I'd rather she left me alone please?
Hate confrontation, but her not being in my life is a welcome relief