Since we have no idea what you actually did with the sex worker, the only thing to comment on is that you clearly don't have an HIV problem you have an anxiety problem. There is an anxiety forum on here. I would recommend, given how long this has gone on according to your post, that you seek therapy with a psychologist who specializes in the treatment of anxiety if you haven't already done that. Also, ever go out of dates? You might find being with someone you actually get to know might tamp down some of your anxiety as well as meet some of your needs. Is your anxiety also preventing you from doing that? Because again, if you have an anxiety problem but you keep trying to fix an HIV problem you don't have, things will stay as they are. Peace.
No risk.
I understand your fear of contracting any dieases. But i feel that you are overdoing. Please dont let this fear ruin your sex life/your life.