Coping With an Event - Any Tips?

My first post and I'm hoping to get some help from you good (and more experienced) people.

I'm due to go to a festival soon which I'm dreading. No, not a music festival, nothing so cool. There'll be a lot of people there and a lot of stalls to see. I'll do as I always do with such events - go very early to be at the head of the queue to get in, whizz round the place at stop speed grabbing anything that interests me and trying not to have to talk to anyone, then exit as fast as possible before it gets any busier and before my panic attack becomes too noticeable.

My tactics are those of a terrified child and I'd like to find some better ways to deal with such situations. Does anyone have any tips or ideas on how to make the event less stressful for myself (and others, come to that)? I should mention that I've tried mindfulness methods and they don't work for me. Any help gratefully received as I'm dreading this event.