Kindergar -- YOU DID WHAT?

I'm sitting here raining tears all over the keyboard. Today was my son's second day of kindergarten... and he punched 3 kids today. It's a bit of a Dr. Jekyll/Mr. Hyde thing with him. He can be very sweet, thoughtful and articulate at times. Other times, though, he does a complete 180. Kicking, screaming, crying. He's big enough now where it's getting physically dangerous to be near him when these moods come on. We first realized we had a serious problem in his first year of preschool...things were not just "boys being boys". He was remorseful and knew the rules, we tried a few ways of correcting the behavior...but it just. wouldn't. stop. The same thing happened in pre-K last year. He would show progress and weeks would go by without incident, and then things would go right back to the way they were...often times worse. His teachers weren't very nice to him and would talk about him as if he were a "bad kid" right in front of him. They let him get under their skin, which was no good for anybody....come to think of it, they weren't very nice to any of us. His peers have started shunning him and he's already been labeled a "bully"...which is like a death sentence these days. The thought of him entering public school is terrifying me right now. I'm so thankful for this website. It feels really good to get this off my chest.