ESH

So, i will preface by saying I don't have experience with this disorder but I do have my own share of other mental illnesses.

You caught her off guard. Her response sucked and she should have apologized and done way, way better.

When you approached her later, you would have done better by apologizing for making her uncomfortable and request that you have a further discussion about it. It seems very strange to me that your mother would react this way to a disorder she knows you have but its also clear she doesn't fully understand it.

It sucks to pander to others when you're the one who is struggling but since, I'm assuming, she's a huge part of your support network, you're probably going to have to meet her halfway sometimes.

If she's still obtuse after that, NTA.