Not sure about your situation, but I wish you luck!
I put lasagna gardens ontop of Florida sand... and just carried on.
Turns out I like sand & clay for planting, even though for the last few years I THOUGHT I hated them!
But sand offers good drainage and the ability to easily dig up things like potatoes, or transplant things like strawberries.
And clay offers really good water retention and frankly takes longer to dry out than other surfaces because it's so dense.
Just saying, sometimes a disadvantage can eventually become an advantage!
Wisher, you are talking about next years garden so no hijacking. I see your problem but wish we could exchange some sand for clay and we both would be happier. Compost, compost, and compost would be my suggestion.