dude im in very similar situation to you.i lost a lot of fat over this year,and now im this skinny guy with no muscle.thats really weird for me , because i used to be a big strong fat kid,and now at 16 im 6 three and thin.i just wannt a general athletic body,i dont care too much about bulking up.now im slowly forming a normal diet,which is bassicly high carbs medium protein and low fat.i think if i just eat well,do light weights and ride my bike alot i will maintain and actually build my shape. i hope.