Lymph Nodes in Neck swollen

I am seeing an HIV positive man, he's been undetectable for 4 years and we only kissed and had oral sex, about 7 weeks ago, and even that was only a brief contact, he did not release anywhere on my body, and did not taste any pre-come. I have recently had a bad case of the flu, and a mild cold, and was out for 9 hours in the cold of baltimores inner harbor, walking around outside on new years eve. Whats worrying me is the swollen gland on the right side of my neck, it's painful to sneeze and to swallow, and I have a lot of mucus production, and I've also been slightly fatigued. I know I may sound paranoid, but I'm just curious as to what is wrong, or what could be wrong? Thanks for all your help!