I cannot count the number of times I've messed up in a similar way. The interesting thing (and probably one of the things I love most about quilting) is that they WILL eventually be perfect for something. Some of the best quilts I've ever made came out of a strong desire not to toss something that didn't work out the way I originally planned. It has forced me to create some original patterns and, in the end, I've been more proud of those quilts than any others. I absolutely understand your frustration, but I honestly believe those mistakes were simply made for another quilt. Keep your chin up!