4 weeks after sex got rash, swollen glands, night sweats, cold sores abnormal cbc high neutro low lymphs. neg for hiv & stds at 6 mon. what caused it?

After sex: That's a long incubation period making it questionable that sexual contact was the culprit. Fortunately hiv and other std were ruled out. Where were the cold sores? If multiple crops were present, a herpes infection or outbreak may have explained all your symptoms. This may or may not have been transmitted by someone else as the virus could have been dormant in your system all along.