A small town secret

If you can guess what this is about i'll mail you a gold star.

A box on the side of the road,
Claiming currency,
Claiming it's not dated.
I won't breathe till we pass over this bridge
I'll gasp air in the waiting room.
You'll leave your head on my shoulder
Till they call out your name
I'll leave you with my courage,
I'll let you take my strength.
Hush pretty girl, don't mind the sting,
Soon you'll fall asleep and I'll pace the hall
They'll take a part of you,
Leave behind a secret
A dam that just won't hold.
Fall asleep in the passenger seat
I'll have you home soon
This whole drive I've wondered,
Are you fixed or are you broken now?
How will I convince tomorrow that I'm worth saving?