As for my fuckup, I talked to my HR person about it, and she pointed out that it wasn't as big an error as I was feeling (you know how that self-sabotaging voice in your head can take responsibility in the worst possible way sometimes?), and then I had a meeting with the person who had brought it to my attention, and I explained why I'd done it the way I did, and she saw it my way and then we had a really productive conversation about next steps. And she didn't ask me to change my approach. So I think it actually wasn't a fuckup at all, except in my mind, and whatever part of me is afraid of getting "in trouble".
Anyway, then I did my end-of-year self evaluation to send to my boss, which was the perfect thing to do, because I know I've been rocking this job, and so I had no excuse to go badmouth myself, and instead, spent an hour carefully compiling a list of all the awesome things I've done since I got here.
And then I went home and drank in good company and had an awesome night of sleep, and now today is Friday.