Instead of one extreme or the other, there may be some way to balance it. The way it stands now, EITHER you push people away OR you are devastated when they leave you. The trouble is, this creates a self-fulfilling prophecy, because both the pushing and the clinging will turn people off and make them more likely to want to leave. It's easier said than done, but perhaps developing a disinterest without actively trying to push anybody away might protect your heart a little better.