I feel so lost...what's wrong with me?

I don't know where I fit in the big mess that is our world. I don't know who I am anymore. I've done drugs...they didn't make me happy. I've had boyfriends...they didn't make me happy. My friends don't make me happy. My family doesn't even make me happy. I'm a quiet person with social anxiety, I'll admit that, but it's never held me back before. I suddenly have no enthusiasm and no peace of mind. I've suffered from an eating disorder in the past and every now and again I lapse and don't eat for a week or so. I can't enjoy anything I used to be able to...reading bores me, television bores me, my friends bore me. I'm so bored! I feel trapped yet I seem to have no boundaries...I've just finnished high school and I'm 16...so I should feel more liberated than ever. But I can't muster up enough strength to care. I used to be strong and be able to hide these feelings with a smiles and jokes but now I can't even do that! How can I fix myself before I lose everyone and everything I care about?