I agree with evaunit. You said sewing wasn't your strong point, and I think the judges saw that. Not saying it's not a good costume, but in the context of a competition, I think it needs some work. Yeah, lights are cool, but those alone shouldn't get you an award.
ACen 2014 cosplay: Lara Croft, Erio Touwa, Shirahoshi Hime
ALA 2015 cosplay: Shirahoshi Hime, Akemi Homura [Haregi ver.], Menma