I hope this doesn't come across in the wrong way because I want you to do nothing more than what is right for you, but be careful how you deal with people. I have a lot of difficulties with my self-esteem and need validation as well and I would love to give you just that, but I wanted to give you a long-term perspective. I understand anxiety, I have ocd, gad and bipolar II and I'm very adept at the art of avoidance, but I also understand that people, situations, and how we view those situations change as we, and those around us, change and grow and possibly conquer our anxiety.

Far too many people do things with a finality that erases any chance of a change of heart or mind. She is your sister and someday when you are both old, gray, toothless, and feeling nostalgic you may want to get in touch with her, hey she's blood, and burning your bridges now may make that impossible later. What we are like now may not be what we are like later in life. I know that my illness has effected and hurt people in my life and some have written me off and it hurt a great deal. It is because of this that I refuse to cut someone out of my life completely and conclusively because I pray everyday that I don’t have to suffer that fate myself.

I'm not saying call her up, forgive her for whatever she has done, and become her best friend. It sounds like you need to avoid her for your sake and maybe smack your husband upside the head in the process. What I am suggesting is taking the most tactful route you can now so that if you need her to donate a kidney to you in 10 years you can still ask her. If nothing else she is a great resource for organ donations!