It sounds to me like you have very high anxiety, so every stressor hits you hard and you overreact. I wouldn't say that you are "mental." I think you might try looking for help dealing with your anxiety. What happened in the aftermath of the argument with your brother sounds like it could be a meltdown, but your initial fight with your brother doesn't seem like a meltdown per se, though if it was the result of your overall stress from having to move, it could be.