hmm, could it be that the ex-gf's actions and personality made you nervous of her "flying away," so you were uncharacteristically controlling about the phone calls? or your fears of being alone are gradually making you more and more controlling in love relationships?
maybe you should do more casual dating. get set up on blind dates, etc.. not that there's anything wrong with being a serial monogamist, but i'm guessing that this lonliness inside is making you grasp at relationships more straongly than maybe in the past.
but don't feel like you are alone in this predicament...lots of young professionals feel really lonely and are single (that's more than half of NYC!).