Mom Refuses to Listen

I don't have any advice for you, because I would just be screaming a big fuck you at my mother (like we always tend to do). I totally understand though, I deal with anxiety issues and I totally get not wanting to attend a party about YOU with people you don't know.

I guess it would really all come down to the preservation of your relationship with your mother. Do you want to keep things civil to the point you're willing to sit through such an event?

I personally have a bizarre relationship with my own mother, but from what you're saying, it sounds like she wants you to be happy on her terms and not yours in this case. You don't have to justify what you want to anyone (except your FI), it's not the nicest way to go about things but if I were you I wouldn't go. But I'm also kind of an asshole.

I would say grin and bear it. Just try to have a good time & thank everyone for the gifts.

If your anxiety is that bad then let her throw it and dont show up. If you guys argue and disagree a lot prepare yourself for the next disagreement or argument and move on. In the end you're an adult and as I've seen on a lot of posts here NO is a complete sentence. If you say no she still plans on doing it, let her spend her money and don't worry about trying to get her to change her mind.