I have meltdowns all the time in class and I'm even medicated. It's so bad, only in 8th grade, that they're currently in the process of sending me to an alternative learning school...AKA hell full of wannabe-gang-members. What's worse is that the school I'm at doesn't even try to help. They offer suggestions like carrying a pass around and handing it to the teacher of whatever class I'm in, waiting for them to call down and say I'm leaving, then leave.
I wish I phrased this better, because they took this as a threat, but I said:
"If you make me wait in a room for even 5 minutes when I'm pissed off, that pass is getting thrown at someone's head, that phone is getting destroyed, and someone could get seriously injured. If I'm going to leave, I need to leave immediately."