HIV risk: nil.
He's probably not HIV+. Even if he were, without him ejaculating in your mouth, transmission risk is nil. Even if he had, it'd be tiny... so small that there are studies saying it could be nil.
It's possible rather than likely that you might have got something else, typically one of the bacterial ones. In a week or two, you can go to a sexual health clinic, tell them you go down on men and get a throat swab.
If you're feeling like this, it sounds like the sex you're having isn't as safe as you'd like it to be. Whether that means learning about the risks or reducing them by using condoms for oral is up to you.