you dieted down too far, and lost alot of muscle. in the pics you posted of when you were fat you couldnt have been more that 25% bf. you lost alot of fat, congrats by the way, but you lost alot of muscle, unfortunately. i think if you had folloewd a typical bodybuilding diet you would have been able to retain alot more muscle.
i commend you on the commitment to the contest. none of the other competitors had anywhere near the amount of dieting to do that you had to, so if the contest was for transformation, you would get first for sure.
you look great, though. really good job. whateva obviously is more developed, but cant be more that 5'6" or so, so your frame hinders you a little bit.