In thinking why I dread opening my inbox, I think it is that I get a lot of emails from people who found my name on the internet and who are struggling with some aspect of their kidney disease, or who are at a center that is suboptimal or who can't get a preferred treatment or are being given a line of bs about why they aren't allowed to do something or are in general fighting with their center. And then there are the people who want me to do something like speak at a function or participate in a project or some advocacy, which I appreciate and there was a time when I did that sort of stuff but right now not so much, but I try to respond since I know what it feels like to be trying to do something and not getting engagement. But it all takes time and energy.
!!!!!!!
This is classic burnout and I'm amazed it didn't happen sooner. This reminds me of a sourdough starter recipe I found on the internet and it was funny (it had nothing to do with disease, which helped with the humor immensely) because the poor author could not convince the internet that he was no longer interested in discussing sourdough starter, despite writing it on every corner of his site. So his FAQ was filled with sarcastic questions like "Since you once put up a website about sourdough starter, shouldn't you be required to answer every email question you receive on that subject forever and ever until the end of time?"
Not sure you qualify as an introvert. I'd say if you don't already have a private email that cannot be found via google, set one up and have friends contact you through that. Set up an autoreply with the other one saying thanks for contacting me but I am unable to answer any further queries regarding dialysis and kidney failure, I wish you the best of luck. It may sound cold, but that's what I'd do.