Not Ready for Kindergarten?

My 5 year old son has a birthday near the cutoff for starting school in our area so we tried starting him "early" this past fall. It did not work out and after two months we pulled him from the program and put him back in daycare. (We both (parents) work full time and there are no options for a traditional preschool available to us that fits that schedule, daycare is our only option). We pulled him because of a lack of support in the classroom, his escalating bad behavior, and the obvious stress it was causing him. Academically he was doing fine and really enjoyed learning. When he would actually sit and do his work he rarely made mistakes, the sitting down and doing the work was the problem.​Fast forward to now and we are back starting the process of enrolling him for school in the fall. And frankly I don't see much improvement in his "problem" areas that all my research told me he would grow out of. He still has a TON of energy and has trouble sitting still. He still has trouble keeping his hands to himself, focus, and self regulation. Basically all the things people mention about why boys have trouble at school, and he has them all. He's a smart kid, but all the other stuff really gets in his way. We talked to his teacher in the fall, as well as pediatrician, about the possibility of ADHD or other "causes" but both were firmly in agreement he did not have a "cause" for his behavior other than being a young boy.I guess I'm looking for reassurance, maybe some commiseration from other parents whose kids aren't perfect and knocking it out of the park all the time (like it seems all the other kids are). I know we still have 6 months till school starts, but parenting, you know?!?! via /r/Parenting http://bit.ly/2RKkFf3