In a wedding this weekend

Hi,

I have been here before for other reasons but the main reason I am here today is because I am in a wedding this weekend that will have 400 people at it and it’s a full catholic ceremony. I usually have to sit in the back whenever I’m at church or weddings because I often have these intrusive thoughts that I’m going to yell something inappropriate out (mainly when it’s most quiet). I typically leave the room when I get this feeling and go somewhere where there is no one else around. I am in a massive wedding this weekend and I don’t know what to do. I have talked to the groom and he supports me but it is too late to back out and ask to be an usher. I was recently in another wedding that was much smaller and did fine as I told myself it was just a thought and wasn’t actually going to happen. Something feels different about this one. I take Xanax when these types of events occur but I feel like I am going to ruin their wedding and I don’t want to walk out of the church in the middle of the ceremony because I feel like I’m going to yell something out and have a panic attack. Anyone else have these feelings before?