Monster in my Head

I have a Monster in my head
It knows, exactly what, I dread
It gnaws and nibbles at my happy thoughts
And soon, all that's left is a load of chaos

There is a Monster in my head : 
It makes me shudder, it makes me scared. 
It comes and goes on its own time;
Isn't my head supposed to be mine?

I'll tell you something : this Monster has no sense: 
It just doesn't know, somethings are best left unsaid.
It speaks the worst things, voices my greatest fears 
I wonder, then, why do I allow it to come so near?

It has its own will, perhaps a mind of its own;
But there must be things to which, even it is prone?

There's a Monster in my head, 
Why don't I take on it, instead?
Maybe turn the tables, be the one it dreads : 
Maybe I can be the Monster in its head!