AIO - A friend replied dismissed me while I was talking about my trauma

So, some context... A friend of mine, I'll (23F) call her Amy (29F), is having a wedding soon. I live on the East Coast, while this friend of mine, whom I met roughly 3-4 years ago online, lives on the West Coast. I've never traveled such a long distance on my own and was already getting cold feet about going, as my flight leaves in a few days. I'll be attending the wedding with the rest of our friend group (roughly 5-6 extra people between the ages of 23-31), whom I also met online. I've never met any of these people in-person before and have been feeling nervous and anxious about attending.

However, the incident in question happened during a conversation about the festivities and how many of my friends were going to be drinking. I tried my best to convey that I have no problems with people who drink and absolutely understand that it's an activity people deeply enjoy. I did feel it necessary to mention to them, though, that I have had past traumatic experiences with drunk people (but I didn't mention the severity of my trauma, such as it being sexual assault), and that, while I don't judge them at all for drinking, I will likely excuse myself during the parts of the event that include it. This is when, as I was trying to clarify that I understand this is a me thing and not at all a them thing, one of my friends in the friend group, I'll call them Brian, interrupted me by saying, "yeah, yeah" in a bored and irritated tone, then continued to dismiss it by saying "ok, yeah" in the same voice when I tried to talk again.

I would say maybe I had been going on a bit, but I had literally only mentioned the traumatic experience part and that I'd probably excuse myself around the time of drinking. Part of me simply just doesn't want to go now, especially when no one else publicly denounced the friend's comment, but reassured me that it was rude only in DMs. I already feel so nervous and like the environment would not be comfortable for me, but I want to be there for my friend and to meet my friends in person.

Would I be overreacting if I decided to cancel the trip?

(Additional context: The entire friend group will be sharing an AirBnB--minus the bride and groom--so it would be difficult to avoid just this friend).