Look up vipassana. This is a Buddhist practise and offered in structured meditation retreats around the world, & where choosing not to speak is not only viewed positively, it is required by all participants, and may give you some insight into the human condition. I have always wanted to attend one but life hasn’t given me the opportunity to do so yet.

I’m autistic and was recently summonsed for Jury Duty. I’m high functioning, and actually wanted to do it but as a single parent it wasn’t possible, so I had a different reason to excuse. Autistic people are part of society too, and we usually have a very strong sense of justice and fairness. But often there are distressing details in court cases, so if your anxiety is likely to be extreme then I think that alone is reason to be excused.