I forgot to mention I have a minor sore throat
Hello, regarding HIV, oral sex is not considered a risky activity, there are no reports of people getting HIV by doing that you did. There is no need to worry or get tested for HIV, however unprotected oral sex might be a risk for other STDs, you could ask in the respective forum if you wish.
About your symptoms, ARS is the first stage of an HIV infection, is the body’s reaction to the infection. Some HIV positive people, but not all of them, reported that around 20 days after their exposure they had fever, sore throat, rash and flu (not cold) like symptoms, all of those came together, or within a few days of difference and lasted for a few weeks. As you see, the same symptoms are present in many other illnesses and not everyone had them, so, we can’t rely on them to diagnose HIV.
The symptoms you describe don't sound like HIV or ARS, but the most importan thing is that you weren't exposed to any risk, and only for that (and not any symptoms or the absence of them) you have no reason to worry.
I have no idea if the sores on your tongue are from the antibiotic or not but they are definitely NOT from HIV.
Check with your doctor if the symptoms persist.