It is good that you can see that the neediness is affecting your relationships, but I don't think that it has to do with bipolar like others on the board. It is more likely a result of interpersonal relationships with your family or others earlier in your life. Being aware is the first step. Maybe you can work on slowing things down in your relationship or talk to her about it (even if things are over to learn from the experience) and also maybe you might find someone who is better fit next time. Good luck!