If you look again at the quilt you want to copy, you will see that there are no square blocks, so no waste by cutting down the diamonds. You have the diamonds in your example placed the wrong way and are using too many of them. Remove the ones at the 4 corners, take out one at top and bottom and place the remaining two the other way, and you will have a block. I would also do the set-in seams. They're not that hard when you practice a bit, and they do look nicer IMHO than having a seam running through the patch.