L.,
The first thing I'll tell you is don't worry, you don't have to jump to counseling. Your son is completely normal. In fact, you just described my son, lol. My six year old was turning into the SAME boy not long ago. To the point where he was getting so physical on the playground in school, he got suspended for fighting...in the first grade...right before xmas break. How humiliating! I was so worried. If he even THOUGHT he was getting in trouble, he'd break down into tears. He is very impulsive, and doesn't think about his actions before he follows through with them. He's always saying no one wants to play with him (I checked with his teacher, & this is SO incorrect, lol), and he's always making comments that he's stupid or something equally disturbing to me & my husband.
Honestly, I was getting really worried too, as I'm sure you are...or you wouldn't be here! A couple years ago my husband had mentioned putting him into some kind of martial arts classes, "for the respect & decipline." I was totally against it because I thought he was already WAY to physical, but in the end he convinced me to at least give it a try.
Over the course of the past few years I slowly started noticing a pattern. His behavior would get worse when he wasn't going to class as often. Long story short, the martial arts school he was going to changed hands, and is now run by a WONDERFUL instructor that has taken a strong interest in my son's behavior. Just in the past two WEEKS we've seen a strong change, and it seems to be working very well. By attending regularly, he's got an outlet for all that energy in a controlled, contained environment. And he's learning how to control it, as well.
I know this seems like the exact opposite of what you think you should be doing for your son, but consider it. Depending on where you live (if your close, I STRONGLY recommend my son's school), check around and find a very highly recommended instructor. It teaches them decipline, respect, as well as self confidence and self control. I hope this helps, and please send me an update on your little angel. If you'd like to talk, I'm here!
PS - We also found that sticking to punishments (not a strong point for us, lol) is also a big deal. When he does something worth punishing, make sure he's not being allowed to slide. It kills me, but my lil guy is grounded for the whole xmas break. He was allowed to open presents & was given a couple hours to play with some stuff. But for the most part, he just gets to see the toys sit under the tree. You do the crime, you do the time, lol. I hate doing it, but it's the only way to teach him a lesson...that he'll remember.