Your breasts certainly aren't a problem, and if your man doesn't want you as much simply because they are small, he's not a man worth keeping. Us humans come in all different shapes and sizes, and there is not a single thing wrong with any one of us. Short, fat, thin, big bum, small bum, big head, small head. I feel the self consciousness with most people today is because of the amount of attention the media gives to your image. You see style and fashion magazines all over the place, all presenting this 'perfect' size 0, large breasted, makeup smothered woman, and a man with a rippling six pack and 12 inch penis. Men worry about the size of their manlihood as much as women worry about the size of their breasts.
If your boyfriend was so bothered about your breasts, would he be with you? I'm almost positive he either doesn't care, or he adores them. I certainly wouldn't refuse intimacy with a woman because her breasts were small. And I doubt he would either