You are certainly doing the right thing by requesting testing.
It is very difficult to help a child unless you know
what the problem
is. His actions at school certainly are typical of someone with ADD. And yes, by now, he certainly may be hating school because he has such a difficult time coping with it.
I would definitely suggest doing some research on ADD/ADHD so you can understand what is going on. You also might want to read, The ADD/ ADhD Answer book." , by Susan Ashley.