Ayyy I wish I could give you a reassuring hug. Her angry flare-up was unwarranted and I urge you to find a way to let it go, as just an unpleasant phenomenon that occurred, like getting splashed in the rain by a passing car, or tripping on a sidewalk. This is just a crappy thing that happened, and it's over. Please go back to the studio there and have some happy experiences to overwrite your bad one.

It's an odd human dynamic, but sometimes the instinct to apologize first will somehow invite an angry response from the other person. If you take anything from this interaction, take the idea that you can always step in when you notice there will be a problem. "Do you have any room to scoot your mat back?"

And ultimately, there's no way to totally shield yourself from other people's anger. It will happen as surely as the sun will rise, and hilariously, it will not even necessarily correlate to times when you're at fault. People can rage over minor incidents or instantly forgive major infractions: it's out of your control. All you can do is your best to be kind and forgiving of both others and yourself, and your best to maintain your own equanimity.