You had no risk of HIV because you can't get HIV from oral sex. You are so safe that you don't even need to test.
HIV is instantly inactivated in air and also instantly in saliva which means it is effectively dead so it can't infect from oral sex. It doesn't matter if you and they were actively bleeding at the time either because the HIV is effectively dead.
Only adult risks are unprotected penetrating vaginal or anal sex or sharing needles that you inject with but you didn't do that so you had no risk. This sentence is all you need to know to protect yourself against HIV.
Even with blood, lactation cuts, rashes, burns etc air and saliva do not allow inactivated virus to infect from oral sex. The above HIV science is 40 years old and very well established so nothing you can add will make your situation a risk.
It is too early for ARS so your symptoms can't have anything to do with HIV even if you could catch it. Only your doctor can diagnose your headaches and nausea, but likely they are the result of fear that you are dying - which you aren't. You can visit the std forum for info on oral std though.