Convince me.

[Keith]

Convince me
Convince me that I am not mad
This padded cell is the home of artistry
And this straitjacket the uniform of creativity.
Using the blood of the wicked as my paint
The bones of the crooked my brushes,
we will paint a mural of the duplex,
the duplex that is my mind. 
For the shapeless and unhuman entities next door
tell me I am sane.

Hi MM
This works well enough and kept my interest throughout but it is a well trodden route you take with the mad artist theme, if you are of a mind to work on the poem then you could look at how you approach the reader, what I mean is you are asking us to convince you you're not mad then you tell us about the padded cell and straitjacket, which is all a bit stereotypical you could try switch this around by giving the reader the artist first and then adding the dark and maybe try a different darkness, I like the bones and the blood of the wicked, not sure sure about duplex it doesn't really fit  in with the rest of your word choices. Thanks for the read Keith