Shouldn't I know things like this?

I remember a couple of years ago at Christmas grandma was taking all of her grandchildren to build-a-bear workshop to make a bear, Charity couldn't come. Before we went in the store Lashelle and I talked she told me about problems she was having and I listened. Now I don't have any idea what is going on with her she was anorexic and nobody ever told me, I suspected just because she is tiny and wasn't eating. Shouldn't a friend know these things? Shouldn't a cousin know these things? I love her so much and I have no idea what is going on in her life, same goes for Dezey she moved out of Jessica's and I have no idea why, I can't mention it because if I say the wrong thing then everybody will get mad. For a while I really thought that Deezey and I were going to be close and now I haven't talked to or heard from her in weeks. I haven't talked to Mourn in forever either. Everytime I think I've found a good friend in my family something happens and it's like nope Erica just kidding. It wouldn't bug me so much if it weren't for the fact that for the most part my family is my friends, I don't have many other ones. I know that I get on people's nerves so I try not to I tried giving Amanda space and where that left me was needing a friend and my mom giving me the third degree. Amanda Dezey and Lashelle are all so important to me and I think they are so amazing I feel like it's my fault that I've lost them like if I were better they would still be here. That's always how I feel in everything, if I was: smarter, faster, funnier, thinner, cuter, nicer, worldlyer, just better then things would be different and maybe I would be happy. If I was a better friend than maybe Amanda, Dezey and Lashelle would actually tell me things and I would actually know them. Shouldn't I know these people if for no other reason than jsut because they are my family? How can a person with such a huge family be so alone?