It all depends on how much you truely loved them in the end.
For me it was easy it there wasn't much love left.
Though if my current boyfriend would to break up with me I have no clue as to what i would do.
Go insane maybe? Try getting your mind off of him and do things that you normally wouldn't do, if you are a poet poetry helps to or maybe writting out it out in a story with your own needing. I know none of these sounds like they would help, but they have helped me in the past