HELP! Imported all the products with updated cost of goods, now all variants are gone...!

Hi experts,

I exported all my products to update the cost of goods. Now after importing everything, all my variants are gone…!

Is there a way to fix this???

I think what went wrong is:

To get all the products with no cost of goods, I clicked to sort A - Z. This might be stupid but I was not aware that the order was so important.