I can't maintain a close relationship, is it normal?

I've had people in my life come and go, only I push them away. I can't really control it, but once someone gets too close or they know too much, I push them out of my life. At what I now call the "Climax", I always get irritated or feel suffocated around them, sometimes they're marked as an "enemy" (one not to be trusted). It's like I know it's not right to be so suddenly detached, but I can't hang on to what feels like a failure. In platonic relationships it takes longer to become a completely unattached failure, but in others, it's a hella lot quicker and the after impact of my unattachment is worse. I'm tired of hurting people and losing good friends, but I'm also tired of not having control over my own actions and emotions with no explanation. Is this normal?