Major, major problem

Can you see it? You'll probably need to click on the photo to enlarge it. As I've worked round cutting out alternate diamonds and getting close to where I've started from, they don't match up. As a plain diamond grid it works fine, but no I had to be clever and make it an alternating grid (what was I thinking?).
I'm sure it can be sorted, but right now I'm not a 100% certain as to how. If I'd used YLI water soluble thread I could just wet the thread very carefully along the lines of stitching, let it dry and redraw the grid (and how I redraw the grid has yet to be finally decided). But I didn't, I used Superior Threads water soluble thread which requires warm water to dissolve it.
I like this thread as it is stronger than the YLI, but this time it will mean unpicking rather than a soak as I can't let the rest of the quilt top get wet and loose my markings.
DH is a mathematician, DD is a Philospher and I'm twixt and between the two. Late last night, I knew DH's solutions wouldn't work and DD just commented that it made her brain hurt as she just couldn't see why and how it had happened.
Tonight we're having dinner with friends. She used to be a high level aircraft designer before she became a quilter. Perhaps she can see a resolution?
Either way, it will need unpicking in at least one corner, and smudging the existing grid lines very carefully (perhaps a damp cotton bud), letting it dry so I can re draw a grid which SHALL match up. That corner of the quilt will look a total mess until it goes in the washing machine to get the marking lines removed.
I have faith there is a way round it, I just am unsure what that way is at the moment.
DH and DD are most sympathetic, they've seen the months of design work and preparation which has gone into this top so far. A very very large Vodka appeared last night to help ease the pain (grin).
On a happier note, way back when we were buying stuff to prepare the cottage for sale, then changed our minds and had to take it back, I ended up with one lot of stuff 3 days past the return date and so had to accept a credit note instead of a refund. We've waited until now to use the credit note as we knew there would be a sale. The curtains in our sitting room needed replacing and whilst I don't normally 'do' ready mades this seemed like an opportunity not to miss. Our sitting room is triple aspect and all the windows have full length drapes. When I made the current curtains I used 44 yards of fabric just for the fronts without the lining. Not a prospect I looked forward to repeating. So these shall be our new curtains. The colour is more duck egg than the grey tones showing on my screen.
When my knee is better, I shall paint the walls a duck egg and liven up the colour scheme with some raspberry highlights (and/cranberry red).
We nearly ended up with the same curtains in a red/terracotta colourway, then DH worried about it looking like an Indian restaurant so that put paid to that (grin).