mouse my take on her response is that she did hear your insecurities about going out and was attempting to be reassuring and lift you up by having you think of yourself being out and having a good time.

I don't think she understood the depth of your not wanting to go out. I don't think most people get that. They feel free to just go an do and they don't know how to think about it possibly being a struggle for someone to do those everyday things. It would never occur to them all the emotions around something so simple as going out so they don't/can't engage with us about it. They just don't know.

She didn't dismiss your feelings of not wanting to go out. She heard what you were saying and was able to quickly find something reassuring to say that wasn't judgemental, questioning you "WHY??? What's the big deal? Just go out!" or the like and was dismissing with a "So? Don't go then.".

I think it's great that you're going even though you feel like you'd rather not and I do hope you'll have a good time!