((((((((((( Christina ))))))))))))
I can say no better words that haven't already been written by the posters to your story.
I, too, want to say that it was in no way your fault. That cretin did it, and it's his responsibility. I also want to say that your sisters are not perfect and you don't know if they are being sexually abused or not. Children of abuse usually try very hard to please the abuser.
I know you are a good, kind and loving person.
Hugs,
Jan