Say it like it is in advance.
The only barrier to your dealing with a meltdown 'privately' is other people. But since there are other people and you are not what comprises your meltdowns, let them know in advance. They likely have already been on the recieving end of your mood swings. It will help them to know what they are so they can take their own soul saving defensive measure.
I start mine like this, "so and so, I am having a really bad day (that's when he takes off-years and we have this down), it's not you, but I am warning you, run"
Once I am 'left alone' long enough to address the underlying issue(in my head) then I am able to resolve the results of the flare. (in my body)
Its all about health. We can't make all of the stimulus go away. We can recognize it's effects on our body systems and take self defensive measures.
Or you can just get on drugs, which is alot of people's only option.
A person, if they loved you, would understand this, once they understand they are in no way a source or a target, but instead a casualty dependant on their actions in the situation.
_________________
"I'm sorry Katya, my dear, but where we come from, your what's known as a pet; a not quite human novelty. It's why we brought you.... It's nothing to be ashamed of, my dear, but here you are and here you'll sit."