Welcome to the forum.
This was a very low risk exposure -- even with a commercial sex worker in an AIDS-endemic area like South Africa. Condoms work, so you needn't worry about the protected vaginal sex; and HIV has never been proved to be transmitted from an oral to penile partner by oral sex.
The risk of other STDs was also low, and no STD can cause itching in the penis only a day later. I wouldn't have recommended the antibiotics you had, especially without medical supervision. But they probably did no harm -- and more importnat, even if you had acquired gonorrhea, chlamydia, or NGU, there still is no reason to be concerned about HIV.
Even though your risk of HIV was zero or close to it, I recommend an HIV test. Most likely the negative result will be more reassuring than anything that I or any other expert can say. Enough time has passed for a reliable 4th generation or "duo" test; and after another week (6 weeks) even a standalone HIV antibody test will be reliable. Below is a link to a thread that discusses the time required for definitive HIV testing:
Let me know your test result and I'll be happy to comment further. You definitely can expect a negative result. In the meantime, your risk is low enough that you can safely have unprotected sex with your wife. That's what I would do if I were in your situation.
I hope this has been helpful. Best wishes-- HHH, MD