While I believe - from mostly my own experience - that managing anxiety, etc. gets easier with time and effort...there are some days that you just have to ride it out. And that's ok. I still occasionally have days that I just take a 'me' day and lay low...
I find in those times it's best to just whittle away things to first principles: you didn't drink. And some days that's plenty... and always the starting point.
You aren't alone.
Be proud that you faced the day and the challenges sober. Sometimes we're courageous even if we feel nothing but. Make sure to give yourself some credit for that. Try to turn that tunnel of anxiety train 180 - sure, there's lots of things you didn't do. But what about the things you DID do...
-B