A breaking apart

I have two friends. They were together, and now they're not. It's all very dramatic and anti-climactic at the exact same time.
Why? Something inexplicable changed. That certain something that a romantic relationship has that your other love filled relationships don't changed, shifted, and is now something else entirely.
What changed? Everything and nothing. What now?

I know the story, I've had the conversations, I've seen the resignation in the eyes. It's all very calming and troublesome. But what is there to do?
The same conversation was had a year ago, and there was no break. Now, a year later that certain something hasn't been recovered. How long do you stay? How hard do you fight? When is it not worth it anymore?

I am absolutely terrified of commitment. Oh, there are lots of reasons why. I can name a name that I've beaten into the ground. I can boo hoo about the fallout of that relationship that paralyzes me still. But my fear of commitment was only birthed from that relationship. It has been weaned on the fractured relationships that seem to be about how deeply you can wound your partner in public. My fear of commitment has been nurtured by lack of faithfulness, honesty, integrity and sacrificial love. It's grown up to quickly on getting mine no matter what the cost. I've seen the wandering eye and heard the cruelty that only someone you've pledged your whole life to love can inflict.
I'm terrified of committing to someone like that. I think that I could be a very committed person, if I thought that it wouldn't evolve into this dull, throbbing disdain for the other person. I could commit if it wouldn't turn into apathy.

But the oddest thing is, I'm most afraid that I'm the person listed above, and that I would exact that behavior on the person I've committed to. I'm fearful that I would become apathetic and fall into old habits of seeking out weaknesses to exploit for my entertainment. The truth is, I'm most likely to turn into the person that speaks so poorly of the one I vow to cherish. I think that's what scares me most of all.

I understand this breaking apart isn't what it seems to be. I understand that it's not a 'one day it's working and the next it's not' type of thing. They're trying to be amicable. They're trying to remain friends because they do still love each other, the love just changed.
This breaking apart has broken so many things. This breaking apart isn't permanent yet, but could be.