Losing It

When I first began this pattern, I had a slightly different concept. But I kept getting the multiple solutions message when I checked logical, so I altered my pattern in an attempt to find a unique solution. I still haven't found a unique solution, but to go any further will destroy the pattern elements I love. Any suggestions on how to turn this into a unique solution puzzle?
Hint: every square diagonal from the corners is filled in.

Identifiez-vous pour jouer