Whats the point of living when you don't have anything to live for?
To experience, create life.

Whats the point of crying when you don't know what your crying about?
People get sad for all different reasons, even for no reason at all. Same thing for crying.

Whats the point of loving when love turns to heartbreaks?
Love doesn't always turn into heartbreak.

Whats the point of doing your best when the best is the worst?
To experience, to try. And since when is the best the worst?

Why is leaving the best for you and the worst for me?
Possibly emotional baggage. The person may heal better. However, it might be better in the end for you.