A negative HIV antibody test at 3+ months, including Oraquick, overrules everything else. You could have had a very high risk exposure (in fact, cunnilingus is zero risk for HIV)
or very typical HIV symptoms (you do not). The blood test proves you don't have HIV.
And by the way, new HIV infections don't cause cough. And influenza and many garden variety respiratory viruses are among the things that result in low lymphocyte count.