What you describe could be a sort of mini-meltdown. The key is not being able to control the reaction, I think.
I remember once when I was a girl, I came home from school to find that my dad had cut down all the small saplings that shielded my favorite running and general nature place from view of the house. I shouted at him and then cried for hours and couldn't have stopped if I'd wanted to -- very out of control behavior for a normally pretty placid sixteen-year-old girl and probably an example of a full-blown meltdown, now that I think about it. Daddy had worried about me going out in the woods by myself and had thought I'd feel more secure knowing I could be seen. He hadn't realized that the whole point was that I hadn't wanted to be seen. It took weeks for me to get used to the new openness of the area, but he never cut down saplings out there again. Looking back on it, I feel kind of guilty about it because he was so bewildered and I'm not sure I ever apologized to him.
Sometimes at work, I'll get overwhelmed when things are moving too quickly and I'll just start crying or get very snappish over little things. For me, that's a sort of mini-meltdown. The same thing will happen if I'm in crowded and confused areas like a shopping mall on the weekend. I just can't process that level of stimulation very well and I lose control of my reactions. Now that I know it's just part of who I am and no amount of exposure will raise my tolerance level to it, I just try to avoid those situations entirely.
This is another thing that everyone experiences from time to time, remember. Even perfectly normal people lose their tempers. It's the duration, level of control, frequency and type of stimulation that seem to set a meltdown apart.