Not saying you are...you'd need to do the research yourself and possibly talk to a therapist, but fear of abandonment is a major trait of Borderline Personality Disorder, and so is anxiety.
http://forums.psychcentral.com/borde...scription.html if you'd like to read up on it and I'd be happy to help with any questions you might have. Not an expert, but I am living with it, for whatever that's worth.