Sorry but oh that made me laugh and want to cry for you at the same time. I thought at first you'd posted it upside down. I've done that by sticking something down only to realise its either upside down or back to front when you open the card.

Personally, I'd salvage that by stamping the message onto a topper and sticking it down on top of the original sentiment. Better still, if you stamp it and then have a fancy die to cut it out with, it will look as though you intended it to be that way all along. It's too pretty to waste.