My son is 8 years old and in second grade. As the school year progresses, his attitude and behavior is declining rapidly. 

It started out that he was a class clown, always talking and making jokes. Then he claimed that he was being bullied. We found out that this wasn't true, that he was actually having emotional outbursts during class, like crying hysterically and yelling trying to get his point across. 

He is a very smart kid, but his grades are suffering, because he either rushes through his work, or flat out refuses to do it. I, as well as his teacher, am tired of having the same conversation everyday. 

He has just been suspended from school, for unacceptable school behavior: He was refusing to do his work, and was shaking the table, which was causing other kids to not be able to do their work. 

I am at my wits end. I have tried everything. Grounding him. No tv. No video games. Spanking him.  
He is now having wild emotional meltdowns at his classmates as well as his teacher. I dont know what to do. Rarely does he have an outburst at home, so I cant figure out what is triggering his behavior.