Kaliope- thank you for sharing your story. I have found too that as I have reduced contact I am more even keeled. That's been a long process for me, first cutting off phone calls, then not going into her home, then not visiting... And it has meant cutting off other family contact, not at all easy.
I have at times not opened the letters. I have talked with my Dad and asked him to stop asking me to call and see her. This move to send letters to my Dad is new. I'd like to be at the point where I never open another letter, but when I set them aside, it often seems they take on a 'larger than life' spot in my life. Hopefully this will be something I can do soon.