Here's my transcription of the Hugh Laurie recording, which I really like. I got with help from a variety of lyrics sites. Laurie says he got the song from Leadbelly.

YOU DON'T KNOW MY MIND
(from Hugh Laurie recording, https://www.youtube.com/watch?v=EE7FHPPCCRA)

Walking down the levee with my head hangin' low
Looking for my mama but she ain't here no more
Baby you don't know, you don't know my mind
When you see me laughing, I'm laughing just to keep from crying

She won't cook my dinner, won't wash my clothes
Won't do nothing but walk the road
Baby you don't know, you don't know my mind
When you see me laughing, I'm laughing just to keep from crying

My breakfast on the table and my coffee's getting cold
And mama's in the kitchen gettin' sweet papa told (???)
Baby you don't know, you don't know my mind
When you see me laughing, I'm laughing just to keep from crying

Sometimes I think my baby's too good to die
Sometimes I think she should be buried alive
Baby you don't know, you don't know my mind
When you see me laughing, I'm laughing just to keep from crying

I wish I had a nickel, I wish I had a dime
I wish I hadn't give myself a bad woman's time (??)
Baby you don't know, you don't know my mind
When you see me laughing, I'm laughing just to keep from crying

Look at you mama, see what you gone and done
You got my money now you broke and run
Baby you don't know, you don't know my mind
When you see me laughing, I'm laughing just to keep from crying

You made me get mad and you made me get sad
The going gets tougher than you ain't never had
Baby you don't know, you don't know my mind
When you see me laughing, laughing just to keep from crying.
When you see me laughing, laughing just to keep from crying.


Songwriters: Clarence Williams / Sam Gray / Virginia Liston
You Don't Know My Mind lyrics © Records On The Wall, Inc, Universal Music Publishing Group