How should I deal with this emotional attachment problem?

I recommend counseling. For you to become more independent and less reliant on him. Also, to find out why he is treating you this way. Does he have a personality disorder such as narcissism that won't allow him to have empathy for how he treats you? Either way, it sounds like you need help from a professional. I suggest contacting a counselor today. They can listen to your issues and help you see things more clearly.