I think one way to get to that acceptance stage is kind of having a bit of a funeral for your love. Make a box of all the things they gave you or your little mementos, cards they wrote and put it away. Write them almost like a bit of an eulogy - acknowledging how much you loved them. And then also taking a moment to realize why it probably wasn't meant to be. This might sound a little bit dramatic, but the first breakup I ever went through, I was so distraught. That was the worst. But if that's not really your thing, keep a diary or some way of tracking your progress. You will probably have a few tears.