You had zero risk for HIV in the first place. Oral sex is only a theoretical risk, and would take some highly whacked out circumstances for it to happen...like a mouthful of blood.
You do not have HIV. I'll go a little further, even though oral sex is not a risk. Your partner tested negative at 6 weeks, that would be a 99%+ conclusive test. So he did not have HIV when you had your encounter. Add to that the fact that there is zero risk for HIV from oral sex and your 5 week negative test....you don't have HIV
Your symptoms? Who knows....see a doctor if they still bother you. It is impossible for them to be caused by HIV.