No offense kid, but if you just went through a growth spurt shouldn't you have, oh I don't know, gotten bigger?. Jeez, 5'10" 125lbs and 12% bodyfat puts you at 110 lean weight. My little sister, who's 5'6" and probably around 10-12% bodyfat weighs 125.
I'm not doubting your knowledge or eating habits, but just for kicks, where do your 4000 kCals a day come from? What kinds of foods are you eating? What kind of training split are you doing? You claim to know more than most the people on the site, why not prove it to us.
p.s. just a little tip, in the future when you're asking people for help or advice, don't tell them you're smarter than them. It puts them off.