ADHD? Look up symptoms on Wikipedia. He may be too young to diagnose though. Also look up Obsessive Compulsive Disorder. This is all I have to offer based on your description. DD was diagnosed ADHD at age 6 and she calmed down a lot on stimulants (I'm not telling you that he has ADHD or that you should medicate, but it's just something to consider).
Sorry things aren't going more smoothly. Keep in mind kids with ADHD can focus very well (or hyperfocus) on things that interest them.