It especially sucks when there's only a particular energy range in which you can control your tone and volume. If I'm too tired, distracted, or stressed, people think I'm upset at them. If I'm excited (usually when around a friend I'm in-tune with), I become too loud. I often don't notice these changes. When I'm excited, I appreciate someone politely informing me that I'm being too loud. But when I'm stressed, I don't have the mental bandwith to modulate my tone. Harping on me about it, or holding it against me, is only going to escalate the issue.
I've learned to outright tell people, "Don't worry, I'm not upset at you. I'm just stressed."
Unfortunately, when I'm past my limit and I desperately need help, I can barely communicate at all. This came up a few months ago at a new job. I was having a shut down and barely squeaked out an, "I need help" while looking at two managers. They looked me in the eye, then completely ignored me. After that I took heavy breaths to try to regulate myself. Unfortunately, the managers mistook my behavior for impatience (they even called my breathing "huffy"), and shortly after they wrote me up for "unprofessionalism."
I was so upset, when I went home I wrote my perspective of the situation. I even included a comic that illustrated what it's like in my brain when I get overwhelmed. I presented it to the top management in my center in an emotional roller coaster of an essay, where I explained that I can't always control my tone, and how I can lose the ability to speak if the stress gets too high. Thank goodness, they were receptive!
Later that same week, we had a meeting with the entire center. The topic was "Professionalism." At first, my heart sank, expecting to feel horrible all over again.
But to my incredible relief, "helping a teammate who's struggling" was highlighted as a core pillar of "professionalism." I was shocked to be vindicated. I've never had someone stick up for me like that, it's still kind of hard for me to believe it happened.