St James Infirmary Blues on slide guitar with vocals

I have stretched myself to try singing and playing this blues standard. Singing is completely new to me. I put a backing track down on a looper and only played slide guitar when not singing to avoid overloading my poor old neurons. I've had fun trying to do this, but would welcome some feedback. Please be kind. You can find the video at http://www.youtube.com/watch?v=QQi9-GruHGk