Hey, it ok to feel bitter. Its part of the 'grieving' I'd say. Same as sadness, anger, disappointment and hurt.

But it WILL get easier. These things always do as time goes by. You'll meet another lady and she will hopefully make you wonder why you felt like this now... Take it easy tomorrow. Do something you like to do, or even do something that she didn't like to do that you did! Take care of yourself.