I'm definitely NOT an expert. However, I would try one or two things - if you think you are going to be critiqued in class you may want to try to sew that section again and 'scrunch' it in a bit. If it were mine I'd probably either do an applique over the top or add a like piece behind and hope for the best. Also, try some fray-check (similar to finger-nail polish but it doesn't harden as much).