How did it go?
It helps me to distract myself with other things, cheer myself up.. To write down worries and considerations, what I want out of the meeting, what the other person might possibly say and how to react to that.. If they disagree or refuse something, what can I do or say then, etc? (Who else can I talk about this if they don't want to do this or such..)
Oh, and make sure you've eaten well (possibly some protein and some fresh veggies, or long-term carbs, to hold the levels of energy) before that too.. Make sure you have some magnesium and/or some other relax minerals/vitamins in nutrition..
Exercise/running may help.. Or talking to other people that you don't have anxiety of.. Or getting a friend/someone trusted to accompany you..
Good luck!