A poem, that I hope you will c/c on?

Simply put, I wrote this poem in the middle of class (I hate math sometimes) and would like to know of ways in which to improve it. Specifically, do you like the repeated lines/ words (I am not sure whether I do or not) and the last line in it. I wrote it because, well, I want to stop wallowing in my sorrow and move on with my life. It is getting old *wink wink*, and I'm just sick of being negative. On that note.....

Drowning in a river,

Tearing down the river bank.

White water and rapids

And freezing misery.

Drowning in a river,

Held down by force.

Sucking in this sorrowful water.

Letting it into my body,

Letting it chill my blood.

Drowning in a river,

Lungs stabbing at my ribcage

And while in agonizing pain

I grin a sick smile

Drowning in a river,

Held down by my own hand.

Clenched around my throat,

Letting go at only my command.

Of which, I will not give.