Convince me.

[Jasper]

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, would sound smoother with "as" before "my brushes" 
we will paint a mural of the duplex, duplex is not the best word to use here
the duplex that is my mind. 
For the shapeless and unhuman entities next door
tell me I am sane.

I enjoyed this poem and your extended metaphor. The contrast between madness and sanity could be better defined, as that got a bit confusing. Overall, great job on this; I liked it.