Okay, let's see what can be said about this one.

I'd recommend not writing about suicide or self-harm in poetry for the most part; if you have a look through the archives here you will find thousands of poems all running along the same lines as this. That's not to say that you shouldn't write about it if it's something you want to write about, but you have to bear in mind that the audience (i.e. other poemranker users) will have seen more 'pain' poetry than we'd like to remember so if you want it to be read, it has to be seriously memorable. Be inventive, be unique, be as original as you can. Read, say, thirty suicide poems on here, note every recurring phrase or image, and never use them in anything you write.
The best way to be creative is by devising new metaphors. Often a poem which is written with a gentle surface but creepier undertones is far more hard-hitting than a poem which just says 'I cut myself'. The ultimate achievement is to write a piece which seems all happy and joyful, but leaves the reader with a nagging doubt until they finally realise that it's about bestial necrophilia. Or something like that.
Next point - the eternal rule is 'show, don't tell'. If you show me a scene with enough clues for me to interpret it, I will be far more interested than if you tell me there's a dead body in a river.
Last point for now (I'll come back to this if you want) - don't write about abstract emotions and concepts too much. Use strong, powerful images (and other poetic devices) and these will automatically carry the force of whatever feelings you're trying to convey.
Well that's it for now, good luck with your writing. I'd advise giving a few comments and votes to people, otherwise you may find yourself lacking - particularly at the moment; hardly anyone's saying anything at the moment.
Peace