I am a very clean person but i was drunk and i gave oral sex to a girl. (i ate her vagina) she told me she was clean. about a week after, i got a serious flu that lasted days and now brain fog and neck pain. do i possible have hiv?

Get tested: A week may be too soon to know if you got infected, and it is too late for you to take post-exposure prophylaxis. Get a HIV nucleic acid test in about 6 months. If that is negative you would be in the clear. You may get tested sooner but a negative result would not rule out HIV, a positive result would be reliable. You have a low risk for HIV. Wish you good health. Get HPV vaccine

Not HIV: Cunnilingus (oral-vaginal contact) is low risk and there has never been a proved case of HIV transmitted this way. And where you live (California) the chance a sexually active young woman has HIV is nearly zero. Your symptoms probably have nothing to do with that sexual contact. Influenza and colds start 2-4 days after exposure. Check w/ doctor; if flu confirmed or suspected, you need Tamiflu Rx.