The Best and the Worst

What is this crap?
Why am I doing it?
It courses through my veins
Leaving me with nothing
And leaving me with everything
 
It's sweet
It's terrible
I love it though,
I feel it kill me
 
Silent death
This pleasure brings
 
Swirls of light and color
This drug brings
Can't even remember the name
Gotta have more
Can't get enough
 
They say love is a drug
I've tried it
They lied
The best drug is that one drug without a name
The one you have  
And you just can't stop taking more
The one that get's you so far up
You can't imagine getting down
 
The worst drug is the one drug that makes you wake up
The one everyone else calls 'sadness'
The one that makes you rip your heart out
If only you knew you had one