Perhaps all a parent can do, in these moments, is let their child be sad; at least for the first little while. Let them have the experience, because it's something we all have to live through at least once in our lives.
Whether the world is ending in 12 days, or my world ends in 60 years when I'm old and grey, I won't take a minute of it for granted, and I will not settle for anything less than a "I want to spend the rest of my life with you" kind of love.
After a breakup, remember, there was once a 'you' before you became a 'we.' You'll recall that there was a time where you were fully whole -- without anyone completing you. There was once a time that you created community, family, stability, and security all on your own.
Living better is often based on clichéd advice and I think it's time to put a stop to it, because frankly, there's some advice, especially when it comes to relationships, that needs to be taken with a grain, heck, make that a whole block, of salt.