I had absolutely no panic attacks, zero issues using the correct bathroom, and oddly enough I didn't particularly want to go home at the end of my day.
I got deadnamed only once. I let it go instantly. I'm not calling anyone out on the name/gender thing for at least a month. Maybe longer, my deadname is somewhat associated with "person who fixes all the things". So it's going to take a while to supplant that one with another, given how quickly and easily it is bandied about.
I used the women's loo a whole three times. The first time was entirely uneventful, and set the tone for calming me down a bit, thankfully. I only ran into someone else face-to-face once, and I was so nervous and shocked, I never even looked up at her face. I let out a strangled half-cry, half-whimper of apology as I pushed past, my hand held to my chest in surprise.
Another time I went in and the larger of the two cubicles was occupied. I had to sit and wait for the other person to leave before I could get my bladder to let go. (I've always had a shy bladder, I guess being in the right bathroom isn't going to resolve that over night.) Otherwise it was not bad.
I don't miss the messes in the men's room. Puddles of urine around the urinal, scraps of paper towel scattered as if by overgrown hamsters. Seriously, some people are downright disgusting (and I'm not singling out the boys here).
The second time I went to use the potty was the best, because I saw one of the young male dude-bro developers from the office down the hall on our floor who I constantly had to contend with for the stall in the men's room. They would go in and sit using their phones for 20-30 minutes at a time when all I needed to do was pee. Seriously. That or simply eye me enough to make me feel uncomfortable and unwelcome, which was almost worse.
Anyway, he came out of their office, obviously heading for the men's room. I studiously avoided all eye contact with him, and as I sat down to pee, I thought, "ha. You don't get to make me uncomfortable about the restrooms any more, guys. Never again."
This day has been pretty epic for me. I don't really want to go to bed.