Xena, I don't think you're having a pity party. Most everyone here can relate. I know I can. And it takes awhile to really see things for what they are. It's natural to want to deny that the people whom you love and who by rights should love you back don't.
I'd say the JWs turned your sister into what she is. My father uses the scriptures to justify his raging anti-semitism, his controlling behavior, and all the rest of his maladjusted behaviors. It's disgusting.
I'm wondering if you have anyone in your life who does love you? Loves you for who you are? Your intelligence? Your compassion? And all those other characteristics that make you who you are.
Do you realize that you are the only one of you in the entire Universe of Universes? That as God experiences life through the experiences of all his children in a limitless universe, that this experience that God enjoys could never be the same if not for you, since you're the only one of you there is? No copies. No substitutes? The universe would not be the same place if you weren't in it. Think of that when thinking of the JWs starts to get you down.
It's hard to realize all this in such a confused and backwards world as the one we live in, but I do feel there will be an answer to all questions about these kinds of perplexing questions about the nature of love - even love from family.
I do hope someone, or a lot of someones, are within your easy reach who do indeed not only love you, but know they do, and aren't afraid to admit it to themselves and to you. We all deserve to be loved. And I hope you're getting your share.
Francois