Are you:
COVID-19
You could say I am royalty,
COVID-19 is a coronavirus, corona is from the Latin for crown, often worn by royalty
and when I am present, most people are quite nervous.
COVID-19 is highly contagious, so people are nervous when it is present nearby
I have a structure that exhibits a regular repeated pattern of component of parts,
The structure of COVID-19 is a highly symmetrical structure built on its parts.
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Image credit: Scientificanimations.com
much better displayed than my rivals.
The structure of COVID-19 is now quite well-known and widely available, propogated by scientists and artists alike. We can see here an example of COVID-19 image searches peaking much higher than those of other coronaviruses (rivals) HKU3 and NL63.

Manually doing those searches makes it easy to see the hits for COVID-19 on an Image Search or also much more likely to return renditions of its structure/form compared to other coronaviruses.
I roll my eyes at people who have metathesiophobia,
metathesiophobia is the fear of change, something that COVID-19 has caused at a global scale unprecedented in recent years
and I have my own fan base of people keeping up with me.
There are groups across the world trying to track, eradicate, and cope with COVID-19 from global mayors coming together, the UN, to any number of international and national groups, both official and unofficial.