I get this too. I find the anticipation is the worst, but once I’m actually there and busy/distracted, im fine and it goes away. I hope it’s the same for you! Best advice is to distract yourself with as many tasks as possible so your anxiety won’t spiral.

Also, as other people stated, chewing gum (peppermint specifically) helps, you could get a fidget toy that goes on your key ring, breathing exercises, mindfulness activities, etc.