I don't know what to do?!

I am 16, 5'10" and 180 pounds (I have dropped 25 pounds throughout last year from removing major stress). I know I am overweight but many say I don't look it. I feel bigger than most and have always wanted to be at a healthy weight but never have been able to push myself there.

I have always been up and down with how I feel about myself. I want to push there and to drop to the healthy weight. I have been told I have a larger muscle mass than most but I still feel unhealthy because of the number on the scales.

Opinions?