Oh my goodness, I am so so sorry. You are so brave to have talked about this and written about it. Its abuse and its wrong, no matter WHO did it to you. And it was never, ever your fault. I'm so sorry you were hurt . Your sister was SO wrong! I really really hope that you can find some extra help. It really is possible to not feel so bad, I promise... things will not always feel this shameful. The shame and the wrong-ness of it belongs to the person who hurt you-- NOT you. You really can heal from this-- its a difficult journey at times, but it CAN be done.