I disowned my extended family to protect my (then) wife, kids and I. I chose my core family over them. Maybe not the smartest thing in hindsight, but I made that choice. I still talk regularly with my Mom. In fact, I am seeing her this weekend.
I would consider reconciling with some members of my family - but not this sister. She is truly a bad person. Since this is a marriage site, I will mention just one aspect. She has slept with MANY married men. That's just the tip of the iceberg.
I am not sure about her birthday. I waver from day to day. She did make a move towards me when she called about 2 weeks ago. That day I was angry and basically shot her down. I understand why she has stayed dark since then.
As for quitting. I have quit trying to save my marriage, because I felt it was my only option. Not because I truly 100% want to. I have not quit caring, hurting etc. And yes, I do hold on. All the time.
Honestly - I have never fully forgiven anyone that deeply hurt me. But then I really only think I have been deeply hurt by one person that really mattered to me - STBX. That may be why I can't detach and continue to hold on.