I can't begin to even fathom the gazillion people who have heard the old chestnut, "It's not you, it's me," as a breakup takes on its inevitable momentum. Even when it's not the dissolution of a romantic entanglement, we're often left questioning why that person wanted so badly to dissociate from us. We turn inward to tear out our own hearts and wonder, "What's wrong with me? Why do they not want me around anymore?"
Here's something to consider: it's the truth. It isn't you...it is them. You have no control over someone else's feelings or actions, so it follows that because they're lowering the boom on you, yes, IT IS THEM! The flaw lies without, not within. There is no amount of repairing a situation that is going to make it hurt less or change the outcome, in the end, since the other party has walked away.
For two-thirds of my life, I've carried one particular rejection around like a stone in my heart. Now I'm trying to admit to myself that it was an irreparable situation from which I should have walked away with a clear conscience and without further burden when I was still a teenager. I was and am, in many ways, a broken person, but if I waited for those flaws to smooth out, I would have had a much lonelier life that I have- So, I guess it's not quitting so much as realizing it was never my fight in the first place. It's a big adjustment.