7 week old cockatiel

Hi my baby cockatiel looks depress now that he has moved into a big cage he turns 7 weeks old tomorrow I only let him play in the cage during the day hoping he Wil bond with the other birds but he has no interest really. The only time he looks happy is when he is sitting on my chest or shoulder. He loves to be carried around like baby. Should I just forget about the cage for now and try it out later again. He loves to sleep with blankets in his nest box he is like a real little human, like his comfort, I raised him from day 1 so he is only use to me not use to birds. Sure he thinks he is a human, just hate to see him sitting in the same spot in the cage like a sad birdy. He eats well and stil in formula, he is healthy and really good at flying. Weight it good really no health issues.