I would suggest some deep thought on this one. I have the same thing but have discovered that what mine is is actually a fear of getting close to someone else. I can be a real charmer and go getter when it comes to relationships. My problem is that once I get to a certain "depth" and begin to feel vulnerable, I panic and begin to sabotage it.

This sabotage can manifest in many forms from just being neglectful to outright hostility and even cheating. It is a very insidious manner that I didnt even realize until lately that I do. Also the closer they are and the deeper the feelings the more likely that "protection mechanism" seems to come on. It is difficult though to determine if their behavior is a "result" of mine or a "cause" of mine.

At this point all I really know is that the more important the relationship and the closer they get to me, the more likely I am to do something stupid to create "distance" or lower their expectations of me.

Just food for thought.