Gah, my best friend.. issues... hate or envy?

I've always thought that I was lucky, for my best friend and I have seemed to be a perfect match. We were and still are unserperable. We have similiar names, and similiar everything. We even look like twins. However, it has always been her that has pulled at the strings of our friendship.

I have come to realize that she is a real piece of work that has done nothing but control my life to the point of suffocation. I have never been an individual, I have always been the sidekick. I have felt compelled to always shadow her like a pathetic stalker, and yet, I have a deep desire to surpass her at everything. And yet, our so called "friendship" has always stopped me from speaking my mind to her, standing up for myself, acting sad when i feel sad, and putting myself out there. And it's not that she threatens me or anything. Quite the opposite. She works her magic in very subtle ways. She will not disagree with me, and if she does, she will do it in a way that makes me feel smart, yet mentally retarted at the same time. It's like she'll treat me and my opinions as if they are coming from a 4 year old. She will help me and back me up to the point where I believe she can keep me safe..

But then, when we are with others, she wil completley ignore me, push me aside, get all close with other people and give me the cold shoulder.. Of course, then, I try to folllow her and ask her whats wrong, and she'll act like the world is coming to an end and brush me off and want me to follow her. And then she'll act very innapropriate and attention seeking at parties in order to make sure the spotlight stays on her. And I dont really like attention all that much, so i cant say im jealous, its just embaressing.. I dont want to go into extreme detail, but she'll do things that make others laugh and or feel sorry for her.. And then, everyone will come up to me and say, "Oh, im worried for her, maybe she'll listen to you." "Oh please help her, poor her." And i find myself repelled to do so.. At that point, it's the last thing I want to do.. Because everytime I try to help, she pushes me away and hits me and so forth..

Not to mention, when I got involved with my boyfriend, everytime I would get even a foot of him, she would jump in between us and get in the way.. Or she'll push her way into everything we do.. And then, he does countless favours for her, and she wont even say thank you.. She takes everyone for granted, and wastes everyone's time just to get attention.. She has toyed with boys and friends for far too long.. She is the ultimate mind fucker..

And yet, I love her.. Its becuase her constant encouragment and comfort when we are by ourselves has kept me coming back for more.. And i've had enough.. But I dont think i can let go... But I want nothing to do with her..

Normal?? What the hell should I do?? Am i being irrational, am i overthinking??