Can a girl help me with how to get a girl the caring way?

Why can't I be ME around any girl at all? I keep pretending to be "popular-ish" when I really just want to be caring and nice. I am not a "let's get laid" kind of guy, I'm more like a "I want to protect you and love you and do almost anything you ask" guy. Could someone PLEASE tell me how to get my girl, hopefully from a girls perspective?