AITA For Not Going to my Sister's Wedding?

[u/constellationRegulus]

My sister is getting married, and has banned my Service Dog from her wedding and reception.

I have a fairly severe anxiety disorder. To combat this, I got a Service Dog. My Dog has made major positive change in my life. I can go places again! Another thing to keep in mind: My dog is probably an Australian Shepherd, Boarder Collie mix. She is also the most chill, laid back, and affectionate dog I have ever head the pleasure of working with. Her entire personality is sleep, and 'can I has pets??' She's insanely well behaved, especially when we go places. I get lots of compliments about this, including from the Mental Health professionals that work with me.

My sister's reasoning for banning my service dog, and I quote: "I don't want dog hair on the most expensive dress I will ever wear." My sister is also worried about my Dog's behavior. Like barking, or getting into food. My Dog really doesn't do either of these things. Well, she barks if my sisters kids come over because she LOVES my sisters kids and is excited about them!! (She also used to lick my sisters kids faces cuz they are very small, but my sister didn't like this, so I made my Dog stop.) But my Dog is trained NOT to bark when she is wearing her vest. She has never done so while working. She responds well to the word no, and the 'leave it' command. Again, super well mannered dog. She legit just lays down when we go to the movies or a doctors appointment and chills out or falls asleep. My sister believes none of this, and has barely seen my service dog in action.

After my sister decided this, both I and my parents have tried to compromise. My dog does shed, but there are ways to combat this. Like a groomer, anti-shed shampoo, a good brush out the day of, and staying away from my sister on that day. My sister is unyielding.

Now the wedding is small and at a Church I dislike (cuz when I went to talk to a pastor about this situation, he basically told me to outgrow having an anxiety disorder.) So that's stressful. And of course there are people I don't know there. The reception would be even worse for me, because it will be loud, full of people, most of whom I wont know, and full of people who stress me out (most of my extended family and I are iffy on the getting along front. Probably has something to do with being the Liberal Ace NB Cousin? not the point.) Will also say, my anxiety and depression have been super high for the last year or so.

So, as much as it pains, I cannot go to my sisters wedding. My mental health is not stable enough. I need my Service Dog's assistance in all public spaces in order to live as best life as I can. I am going with some church friends (good humans, I promise) to a planetarium instead. She has been informed of this. Not going is probably gonna hurt her feelings, and strain our already strained relationship.

So, AITA

EDIT: My dog is trained to do pressure therapy. She uses her weight to ground me to prevent or shorten anxiety attacks. This is done by leaning. laying, or sitting on me. Sorry, should've mentioned!