Is there any way to busy yourself at this event? Can you offer to help out in some way? I get a great deal of anxiety at events I regularly find myself committed to attend. I practise avoidance by finding something to do to assist preparing, then facilitating, and follow-up. Example, at a dinner function I will busy myself in the kitchen before and after. It means less interaction with, in my case, people I find intimidating.

On the other hand it seems you have every reason to mingle and do so with your head held up high.