What you have descried sounds a lot like my son. My wife and I started to notice problems with him when he was in the second grade. There were no major problems before that because he pretty much got whatever he wanted, and it took the school work to elevate his frustration level for it to become noticeable to the point where we needed to do something. Long story short, he is on the high end of autism. Not Asperger’s, we’re told, but shows many of the same symptoms. We had the school evaluate him and adjusted his school work. We took him for counseling for his anger and inappropriate behavior/ frustration, and have had him in a horse riding for autistic children (this is why we own horses now, but another story). He is 11 now and has turned into a great young man. He is off the chart smart when it comes to his school work. We no longer worry about him at school and with other children. I think he can talk to horses too, he can get them to do anything.
We struggled a long time before he was diagnosed. I too, struck out thinking he just need more discipline. I offered a spanking and timeout one day for something he would not do, he said OK, spank me and I’ll go to T/O and started crying. I think the light finally lit at that point. I was raised by a strong hand and that is how I raised my daughter and she has turned out (in my eyes) perfect. However this approach would not have worked with my son. Had I not change my way of thinking when I did, I know my and his life, would be hell now.
I would have your son evaluated. Read “The best kind of different”, By Shonda Schillings.