This is one of the best questions I've seen here. You aren't asking about the encounter again but how to get over your anxiety. Right on! Because anxiety is your problem. This is a mind disease and not HIV. Do they have mental health doctors in your area? This would be your next thing to do. Talk to a mental health professional about the disorder of anxiety. When all evidence is in and you will not accept it and you KNOW this is a problem (the not accepting it part)--- you work on the root of the problem. Not your sexual encounter but your mental health. Hope you do that---