Regulation of emotions

I've noticed that my emotions often tend to be misinterpreted if not seen "too easily" to be considered polite.
Most of it includes things I don't really think about. My fave is naturally "frowning", and my natural stance is a hug like hold on myself seen as arms folded like I'm angry. People also say I'm "looking at them wrong" or like I'm glaring at them.
This is almost always unintentional and not because I'm feeling any certain way. Most of the time I'm just lost in my own thoughts or caught up remembering or focusing on music or something someone said.

I can usually not appear too offensive though if I really focus on keeping my arms looking relaxed (even though it's very uncomfortable and not relaxed to me) and looking at people's eyebrows while focusing on keeping my eyes opened uncomfortably wide. It also helps if I focus on keeping my mouth in a slight smile. I can do all of these but if I do its hard to focus on any conversation.

My second issue with communication is "tone policing", I have virtually no control over tone and cannot tell the difference between when I say something happily or angerly. I seriously can't short of screaming and even then the excitement/anger border eludes me.
I'm often told I've said something in a hateful or angry tone and half the time I'm like "well I'm mad so it's going to sound mad" and the other half I'm not mad until the confrontation so I have no idea why I'd come across as angry. But usually I'm chastised for "being angry" which does enrage me, for being untrue and being a BS reason to be in trouble. People get mad, get over it.

I've got body language so that I can more or less pull off being non offensive, but no clue on regulating tone. Maybe there's tips I've never even considered. But even body language alone exhausts me. plus it does seem like people want a reason to be angry at me anyway.