I'm not sure if this will work but it is worth a shot. It looks like you have a bit of excess fabric so you may be able to take in the seam where the white meets the orange on your too long point. Set you machine to a longer sticth length like a basting stitch. Start out on your existing seam line about where the inner point intersects and slowly increase your seam allowance to try and shorten up that point. Not sure if my written explanation makes sense. I don't know it will work which is why I suggest a long stitch so it is easy to take out. If it does work resew over the basting stitch with your normal stitch length. Beautiful pp block BTW.