How do I trust myself?

Do you often get the feeling that there is some better way to be living your life? That somehow we're just deceiving others with false pretense? Lately that's how I've been feeling. I have been "cheating" at life. I'm not really living, but pretending to do so. I have little tricks, habits, obsessions and addictions that dictate my life. It's not real. I often don't know who's in charge-me or my obsessions. Can the two actually be separated?
I'm not happy with my coping mechanisms. I resort to old habits, like weighing myself too much, trying to control what I eat, creating lists of things to do in my mind, cleaning when nothing is dirty, and cutting myself. Where the hell did that last one come from? I am an intelligent person and I feel like I should know better, but I get to a point where I just don't care. It's a form of self punishment. If I keep it a secret, then I start to go crazy. If I tell people, I feel crazy and stupid. I hate that I don't tell Zach these things, and then I feel like if I can't talk to him about it then I shouldn't talk to anyone about it. Ultimately it's me that I'm hurting and deceiving, but somehow that doesn't resonate with me. I don't feel like I'm important enough to acknowledge the hurt. Then nothing feels important anymore. There are so many people in this world. How can they all be significant?
I just don't know how to deal with this-the feelings of insignificance and the stresses of life. I think I'm dealing with it just fine, and then I feel hopeless. I am staring destruction in the face, what looks like a shattered image of myself, and I don't know what's real.