I'm scratching my head on this one. While you will eventually get to know your co-workers, and repeat customers/clients, there will always be new/occasional customers/clients. There is no way to know everyone you will deal with all of the time. Your best bet is an "inside" office job, or a factory/warehouse/light industrial position where you won't be dealing with the public. Then you will deal primarily with co-workers. Bear in mind some office jobs are "inside" in that you work mainly with co-workers and not the public. Other office jobs are "outside." That is, you deal also with people from outside the office. They could be from other offices, or branches, or customers/ clients, or service people, vendors, sales staff, etc. Also, even in an inside office job you may have to talk on the phone with strangers sometimes.
If you have such a hard time with strangers, I don't recommend self employment, as you would have a hard time dealing with customers/clients.
I am a very shy person with social problems. When I was young I went to many job interviews. I also had many temp assignments. This eventually helped me to deal better with my shyness. I still have it, but it no longer holds me back. Perhaps you should work temp assignments for a couple of years to help you get used to dealing with strangers.
Another benefit I got from all those temp assignments was that I was exposed to people of all economic, ethic, and racial backgrounds on a regular basis, so I got comfortable working with people of all backgrounds. Thanks to this I really don't care what people look like. I care how they treat other people, and that's the way it should be.
Good luck with your job search!
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If a man does not keep pace with his companions, perhaps it is because he hears a different drummer.
Let him step to the music which he hears, however measured, or far away.--Henry David Thoreau