The Glassmaker

As I delve into the mysteries of my heart,
I realize I can't be entrusted with it's care.
So I held my fragile piece out
To you, cracked, and fixed yet again.
I held it out,
Just to have it shoved back,
Forcefully, into my hand. It broke,
The pieces stabbed into my hands,
It's contents mingling in my blood.
So I turned around,
Walked away, already fixing my heart again.

Each crack in this heart
Tells a new story.
This line here is the story of Susan,
While this one is Mary Elizabeth.
Each line bears a name,
And a little glue, too.
How many breaks, though,
Can this little heart take
Before the glue won't stick anymore?
What happens when it won't hold?