You're Gonna Be Sorry You Let Me Down is the very last song the Carters recorded in 1941. The JOAFL tried to trace this song and could n't find the source.

It certain could be a song by Maybelle. Anyone

YOU'RE GONNA BE SORRY YOU LET ME DOWN- Carter Family 1941

You told me once, dear, I was true and kind
You told me then, love, that you were mine
But now you tell me that you were blind
You like your parties and good times

I'm sorry, darling, 'cause you feel this way
Once you told me truthful, to my face
You've found another to take my place
All dressed in diamonds, pearls and lace

    I'm sorry, darling, 'cause you let me down
    A truer love now you think you've found
    But when I'm laid deep down in the ground
    You're gonna be sorry you let me down
    [INSTRUMENTAL BREAK]

So now I've lost you, but still have faith
That you will see the mistake you've made
And when you find, dear, that you were wrong
You'll ask forgiveness and come back home

I believed you, darling, when you said to me
That we'd be happy, we'd be free
But now I found, dear, a fault in thee
When we were wed, love, I could not see

    I'm sorry, darling, 'cause you let me down
    A truer love now you think you've found
    But when I'm laid deep down in the ground
    You're gonna be sorry you let me down