jojo2305-Congrats on fantastic score for your DS. I agree with other comments that schools are more worried about SATs and they are definitely getting tough. There can be other reason which may explain why your DS doesn't seems to enjoy at school?
My DS had bit similar issue at his previous school(his few friends left for independent and I suspect he became a loner-there were surely other reasons but he was not getting desired support from teachers which made him agitated I guess)-his performance dropped ,not enjoying at school and first time he was not willing to go to school . That was a turning point for us.
We changed his school in Yr 6 (in Jan this yr) and all of a sudden he changed again to his usual self. Made new friends-sometimes change of scenery helps.
Now he has just completed 6 weeks at SHSB and have settled well. Wakes up himself and willing to run away to school
So don't let any negative thoughts spoil this moment of happiness -I am sure he would be fine and congrats once again.