How did I get myself into this?

So, today I am going to a wedding for my friend. Tough stuff, to be sure. I cried at her bridal shower in the bathroom while we were supposed to be laughing and playing silly games and laughing a bunch. I cried in my hotel room bed when we got back from the casino at the bachelorette party and everyone else had fallen asleep, and i couldn't because I was just so sad that i didn't get to be that bachelorette. Not only did I agree to attend the wedding, but I have signed on to do a bridesmaids hair, the maid of honor's make up, and the bride's make up before the big moment. This week I was thinking about it and feeling pretty proud of myself for not falling apart or really having too much anxiety at all. This morning it feels different. Like, really apparent that I have bit off more than i can chew. Now I am feeling a fuck ton of anxiety that I am going to mess this up for the bride, not because of some dark side of me that wants to sabotage anything, but because what if I can't keep it together and I leave the bride with one eye full of shadow and I pass out or something? I realize this is probably not going to happen and I am being overly dramatic but this is widow brain at it's finest, I suppose.
The funny thing? I have a date to the wedding. It is super casual and just a friend of mine, an old friend who I have known since grade school. He is a great friend to me, very sweet, likes to dance and party so he is a perfect wedding date. But it still feels really weird. Almost like a real date, I guess. yea, I guess this is what a date might feel like, only more weird. So maybe I should look at this as like a practice date. It's safe, because it's my friend. This could be a valuable experiment I suppose. It still kinda wigs me out a bit though. This is an event where KC should be by my side and I should be 100% happy, and not feeling anything remotely resembling things like dread, anxiety, jealousy, bitterness or anger. But here I am, Saturday morning healthy and ready to go to a wedding for two beautiful people who love each other and all i can muster is gentle sadness and a stomach ache.
Congrats to the bride and groom, I would like to go climb in a hole now.