Hate it when stuff like that happens! One of the toughest things to learn is when it is time to walk away instead "just this one thing more".
Or it is just amazing how a picture posted here will show you in 2 seconds what you missed for 2 months of work on the project.
Ginger K -- sometimes if the blocks are ok and the sashing is wonky, if the sashing is wide enough just cut through in the middle, trim it, and put it all together with a fresh piece of fabric -- which maybe then you can also use for the binding. It's the same idea of making a narrow border for blocks that aren't quite perfect -- just make them all consistent and have enough left for both seam allowance and to show. Doesn't work for narrow sashing though.