I see no signficant chance you have
HIV. Of all causes of swollen lymph nodes, in the
neck or anywhere else,
HIV is one of the least likely of all. You describe a low risk sexual lifestyle with respect to HIV. In short, I agree with your PCP. But you don't say anything about HIV testing, which of course is what you need to calm your fears. If you have been tested with negative results, at least 6 weeks after your last sexual encounter, then for sure you don't have HIV.