I understand not being able to move on, to a point. I am certainly not one to forgive and forget very quickly, and I've been known to hold some serious grudges. But we only get a little while to be in this glorious world, and I cannot imagine living my life so consistently upset that I would waste days, or even years, holding on to something I could no longer change, or was no longer really relevant. At some point, you have to decide that YOU are more important, and that you are going out and making something of yourself. I hate to see a life wasted in the pursuit of stoking the coals of negativity.
Truly, it is. Should you feel a need for revenge against the one who wronged you, then make something more of yourself. Be happy, move on, get a life. Don't keep that back burner going. It's not worth it, and it only burns you from the inside out.
Making excuses for why you can't move on is sad. Blaming others for your inability to move on is pitiful. Right up there with blaming others for your not being able to do the things you want to do.
Don't miss out on the good stuff because you're too busy shoveling fuel into your fire.