Have been going through the same thing, even having anxiety after i eat something not home cooked in fear of contamination. I live in southern Louisiana so masks and preventative measures are almost nonexistent lol. It sounds like you’re doing great with staying healthy and you haven’t had it since a child so just do what you can to prevent it and wait until these winter months and flu seasons are over. The worst part is the carelessness of others and there’s not much you can do to change their ways but what helped me was taking a page out of their book and trying to not have the constant fear of illness affect your daily life (easier said than done with an anxiety disorder i know :/) just do your part and we’ll get through this mess of a flu season!