Hello nicole_hello: I see this is your first post here on PC. So... welcome to PsychCentral… from the Skeezyks!

I hope you find the time you spend here to be of benefit.
Well... the Skeezyks has left a long trail behind him of people he was not nice to.

(Some of them deserved it... some did not.)

Anyway, in my case, I never went back anywhere where I might encounter any of them. And, nowadays, I lead a pretty-much thoroughly solitary lifestyle. So it's unlikely I will ever encounter any of them.
As I'm sure you're aware, starting up your own business comes with its own set of anxieties. So to some extent whether you look for a job with an organization, or start your own practice doing whatever it is you do, it becomes a matter of choosing which set of stressors you prefer to deal with. In reality, it may be that you are more sensitive about things you did in the past than are the people you did things to.
Personally, I would think that for you to start your own business as a sole practitioner in order to avoid encountering someone you think you may have been mean to at some point in the past is not a good way to start out in self-employment. But then, you know more about your situation than I do obviously.
If possible, perhaps you might consider checking out the possibilities as far as working for an organization goes first. And if that appears not to be feasible, then consider self-employment again. As far as how to handle your anxiety goes... well... if you can't get past it on your own, then the "mainstream" answer is, of course, therapy... someone you can talk how you feel about all of this through with over a period of time. But, then, perhaps you are a counselor or therapist yourself?
PsychCentral is a great place to get information as well as support for mental health issues. There are many knowledgeable & caring members here. The more you post, & reply to other members’ posts, the more a part of the community you will become. Plus there are social groups you can join & chat rooms where you’ll be able to connect with other PC members in real time (once your first 5 posts have been reviewed & approved.) Lots of great stuff! So please keep posting!