Your chances of being infected with HIV are actually pretty low as most people don't have HIV.
The symptoms of early HIV can occur with MANY other illnesses, so there is no reason to freak out about it.
I agree that following up with your doctor is a good idea - maybe you have another virus, like a cold or something.
Aj
It takes 3 months for HIV to show up on a test, so I hate to say it but you are going to have to get retested at the 3 months period of HIV and syphilis. Hang in there kid. Infact, if you know how get in contact with the girl, talk to her about it and find out if she has ever been tested./had any stds/past sexual history. I'd like to say it is not HIV and something else, if that. When you read stats, unless it is specific, it is talking about the whole world, and South Africa is the highest HIV area in the world.
When you go in for your results, mention your symptom(s) and if your tests come back negative, talk to them to see if it could be some other bacterial/viral problem.