It's called "With Tears in my Eyes" and was written, I believe, and certainly sung by the great Hank Williams.
was it this one?
"No more to be sweethearts, no more to be friends,
Just give me a chance, Dear, and I'll make amends,
The past is a flower, that withers and dies,
I just can't go on, Dear, with tears in my eyes"
Further full lyrics available on request.