The dunes of darkness 

A black castle,

Sitting in darkness,

A heart of confinement.

A rager is what I'm called.

Beneath my castle,

My own heart,

A place to be wary of.

I sit on my throne,

Yet I rule not.

Foes, like allies,

Surrounding me

For my spoils.

What!? How can I live?

My thoughts, the marching darkness

Beneath my castle,

Mine own heart.

Who could I blame,

When I know nothing?

I sit not knowing what might become of me 

But I rule, I rule, 

Almost driven to madness 

By my subjects,

They control me now,

Sharing whispers with the darkness

For my falling short.

They ride my horses and give the commands 

My inevitable thoughts

How can I get rid of you? 

In this Castle of mine.

KEY EXPLANATION::::

If you wish for explanation.....

You can read this.

The castle is the heart in this context 

Foes like allies is understandable they are your thoughts.

The subject are our thoughts,

They make us look fragile like we can't control them.